ADN -- (Advanced
Digital Network)
Usually refers
to a 56Kbps leased-line.
ADSL -- (Asymmetric
Digital Subscriber Line)
A DSL line where the
upload speed is different from the download speed. Usually the download speed is
much greater.
Ajax --
(Asynchronous JavaScript and XML)
A way of
including content in a web
page in
which javascript code in the web
page fetches some data from a server and displays it without re-fetching the
entire surrounding page at the same time (hence the 'Asynchronous')
Often
(but not always) the data fetched by the javascript code is in XML format.
It is
common for Ajax applications to update the Ajax content multiple times without
the surrounding page needing to be updated even once.
A
simple example of Ajax would be a weather-forcast box in the middle of a web
page. Ajax could be used to populate the box every 5 minutes without needing to
refresh the surrounding page.
The most common
web server (or HTTP server)
software on the Internet. Apache is an open-source application originally
created from a series of changes ("patches") made to a web server written at the
National Center for Supercomputing Applications, the same place the Mosaic web browser was
created.
Apache
is designed as a set of modules, enabling administrators to choose which
features they wish to use and making it easy to add features to meet specific
needs inlcuding handling protocols other than the web-standard HTTP.
A
small Java program that
can be embedded in an HTML page. Applets
differ from full-fledged Java applications in that they are not allowed to
access certain resources on the local computer, such as files and serial devices
(modems, printers, etc.), and are prohibited from communicating with most other
computers across a network. The common rule is that an applet can only make an
Internet connection to the computer from which the applet was
sent.
Server software that
manages one or more other pieces of software in a way that makes the managed
software available over a network, usually to a Web server. By
having a piece of software manage other software packages it is possible to use
resources like memory and database access more efficiently than if each of the
managed packages responded directly to requests.
ARPANet -- (Advanced
Research Projects Agency Network)
The precursor
to the Internet. Developed in
the late 60's and early 70's by the US Department of Defense as an experiment in
wide-area-networking to connect together computers that were each running
different system so that people at one location could use computing resources
from another location.
ASCII -- (American
Standard Code for Information Interchange)
This is the
defacto world-wide standard for the code numbers used by computers to represent
all the upper and lower-case Latin letters, numbers, punctuation, etc. There are
128 standard ASCII codes each of which can be represented by a 7 digit binary
number: 0000000 through 1111111.
ASP -- (Application
Service Provider)
A organization
(usually a business) that runs one or more applications on their own servers and
provides (usually for a fee) access to others. Common examples of services
provided this way include web-based software such as Calendar systems, Human
Resources tools (timesheets, benefits, etc.), and various applications to help
groups collaborate on projects.
A high-speed
line or series of connections that forms a major pathway within a network. The
term is relative as a backbone in a small network will likely be
much smaller than many non-backbone lines in a large
network.
How much stuff
you can send through a connection. Usually measured in bits-per-second
(bps.) A full page of English text is about 16,000 bits. A fast modem can
move about 57,000 bits in one second. Full-motion full-screen video would
require roughly 10,000,000 bits-per-second, depending on
compression.
In common usage
the "baud" of a modem is how
many bits it can send or
receive per second. Technically, baud is the number of times per second that the
carrier signal shifts value - for example a 1200 bit-per-second modem actually
runs at 300 baud, but it moves 4 bits per baud (4 x 300= 1200 bits per
second).
Information
consisting entirely of ones and zeros. Also, commonly used to refer to files
that are not simply text files, e.g. images.
A single digit
number in base-2, in other words, either a 1 or a zero. The smallest unit of
computerized data. Bandwidthis usually
measured in bits-per-second.
A blog is
basically a journal that is available on the web. The activity
of updating a blog is "blogging" and someone who keeps a blog is a "blogger."
Blogs are typically updated daily using software that allows people with little
or no technical background to update and maintain the blog.
Postings
on a blog are almost always arranged in chronological order with the most recent
additions featured most prominently.
It is
common for blogs to be available as RSS feeds.
A measurement
of how fast data is moved from one place to another. A 56K modem can move about
57,000 bits per second.
Generally
refers to connections to the Internet with much greater bandwidth than you can
get with a modem. There is no
specific definition of the speed of a "broadband" connection but in general any
Internet connection using DSL or a via
Cable-TV may be considered a broadband connection.
A Client program
(software) that is used to look at various kinds of Internet
resources.
A shorthand
appended to a comment written in an online forum.
A set of Bits
that represent a single character. Usually there are 8 Bits in a Byte, sometimes
more, depending on how the measurement is being made.
CDMA -- (Code
Division Multiple Access)
A protocol for wireless
data and voice communication, CMDA is widely used in cellphone networks, but
also in many other data communications systems. CDMA uses a technique called
"Spread Spectrum" whereby the data being transmitted is spread across multiple
radio frequencies, making more efficent use of available radio spectrum. There
are a number of additional protocols built on top of CDMA, such
as1xRTT (also called
CMDA2000).
CGI -- (Common
Gateway Interface)
A set of rules
that describe how a Web Server communicates
with another piece of software on the same machine, and how the other piece of
software (the ?CGI program?) talks to the web server. Any piece of software can
be a CGI program if it handles input and output according to the CGI
standard.
The most common
name of a directory on a web server in which CGIprograms are
stored.
A software
program that is used to contact and obtain data from a Server software
program on another computer, often across a great distance.
EachClient program is
designed to work with one or more specific kinds of Server programs, and
each Server requires a
specific kind of Client. A
Web Browser is a specific
kind of Client.
The most common
meaning of "Cookie" on the Internet refers to a piece of information sent by a
Web Server to a
Web Browser that the
Browser software is expected to save and to send back to the Server whenever the
browser makes additional requests from the Server.
Depending on
the type of Cookie used, and the Browsers' settings, the Browser may accept or
not accept the Cookie, and may save the Cookie for either a short time or a long
time.
Cookies might
contain information such as login or registration information, online "shopping
cart" information, user preferences, etc.
When a Server
receives a request from a Browser that includes a Cookie, the Server is able to
use the information stored in the Cookie. For example, the Server might
customize what is sent back to the user, or keep a log of particular users'
requests.
Cookies are
usually set to expire after a predetermined amount of time and are usually saved
in memory until the Browser software is closed down, at which time they may be
saved to disk if their "expire time" has not been
reached.
Cookies do not
read your hard drive and send your life story to the CIA, but they can be used
to gather more information about a user than would be possible without
them.
CSS -- (Cascading
Style Sheet)
A standard for
specifying the appearance of text and other elements. CSS was developed for use
with HTML in Web
pages but is also
used in other situations, notably in applications built using XPFE. CSS is
typically used to provide a single "library" of styles that are used over and
over throughout a large number of related documents, as in a web site. A CSS
file might specify that all numbered lists are to appear in italics. By changing
that single specification the look of a large number of documents can be easily
changed.
Term originated
by author William Gibson in his novel Neuromancer the word
Cyberspace is currently used to describe the whole range of information
resources available through computer networks.
DHCP -- (Dynamic
Host Configuration Protocol)
DHCP is
a protocol by which a
machine can obtain an IP
number (and other
network configuration information) from a server on the
local network.
DHTML -- (Dynamic
HyperText Markup Language)
DHTML refers
to web
pages that use a
combination of HTML, JavaScript,
and CSS to create
features such as letting the user drag items around on the web page, some simple
kinds of animation, and many more.
DNS -- (Domain Name
System)
The Domain Name
System is the system that translates Internet domain
names into IP
numbers. A "DNS
Server" is a server that performs
this kind of translation.
The unique name
that identifies an Internet site. Domain Names always have 2 or more parts,
separated by dots. The part on the left is the most specific, and the part on
the right is the most general. A given machine may have more than one Domain
Name but a given Domain Name points to only one machine. For example, the domain
names:
matisse.net
mail.matisse.net
workshop.matisse.net
can all refer
to the same machine, but each domain name can refer to no more than one
machine.
Usually, all of
the machines on a given Network will have the same thing as the right-hand
portion of their Domain Names (matisse.net in the examples above). It is also
possible for a Domain Name to exist but not be connected to an actual machine.
This is often done so that a group or business can have an Internet e-mail
address without having to establish a real Internet site. In these cases, some
real Internet machine must handle the mail on behalf of the listed Domain
Name.
Transferring
data (usually a file) from a another computer to the computer you are are using.
The opposite of upload.
DSL -- (Digital
Subscriber Line)
A method for
moving data over regular phone lines. A DSL circuit is much faster than a
regular phone connection, and the wires coming into the subscriber's premises
are the same (copper) wires used for regular phone service. A DSL circuit must
be configured to connect two specific locations, similar to a leased line
(howeverr a DSL circuit is not a leased
line.
A common
configuration of DSL allows downloads at speeds of up to 1.544 megabits (not
megabytes) per second, and uploads at speeds of 128 kilobits per second. This
arrangement is called ADSL: Asymmetric
Digital Subscriber Line.
Another common
configuration is symmetrical: 384 Kilobits per second in both
directions.
In theory ADSL
allows download speeds of up to 9 megabits per second and upload speeds of up to
640 kilobits per second.
DSL is now a
popular alternative to Leased Lines and ISDN, being faster than ISDN and less
costly than traditional Leased Lines.
Email -- (Electronic
Mail)
Messages,
usually text, sent from one person to another via computer. E-mail can also be
sent automatically to a large number of addresses.
A very common
method of networking computers in a LAN.
There is more
than one type of Ethernet. By 2001 the standard type was "100-BaseT" which can
handle up to about 100,000,000 bits-per-second and can be used with almost any
kind of computer.
An intranet that is
accesible to computers that are not physically part of a companys' own
private network, but that is
not accessible to the general public, for example to allow vendors and business
partners to access a company web site.
Often an
intranet will make use of a Virtual Private Network.
(VPN.)
FAQ -- (Frequently
Asked Questions)
FAQs are
documents that list and answerthe most common questions on a particular subject.
There are hundreds of FAQs on subjects as diverse as Pet Grooming and
Cryptography. FAQs are usually written by people who have tired of answering the
same question over and over.
FDDI -- (Fiber
Distributed Data Interface)
A standard for
transmitting data on optical fiber cables at a rate of around 100,000,000
bits-per-second (10 times as fast as 10-BaseTEthernet, about twice as
fast as T-3).
A combination
of hardware and software that separates a Network into two or
more parts for security purposes.
FTP -- (File
Transfer Protocol)
A very common
method of moving files between two Internet sites.
FTP is a way
to login to another
Internet site for the purposes of retrieving and/or sending files. There are
many Internet sites that have established publicly accessible repositories of
material that can be obtained using FTP, by logging in using the account name
"anonymous", thus these sites are called "anonymous ftp
servers".
FTP was
invented and in wide use long before the advent of the World Wide
Web and originally
was always used from a text-only interface.
The technical
meaning is a hardware or software set-up that translates between two dissimilar
protocols, for example America Online has a gateway that translates between its
internal, proprietary e-mail format and Internet e-mail format. Another,
sloppier meaning of gateway is to describe any mechanism for providing access to
another system, e.g. AOL might be called a gateway to the
Internet.
GIF -- (Graphic
Interchange Format)
A common format
for image files, especially suitable for images containing large areas of the
same color. GIF format files of simple images are often smaller than the same
file would be if stored in JPEG format, but GIF
format does not store photographic images as well as
JPEG.
1000 or
1024 Megabytes, depending on
who is measuring.
Invented at the
University of Minnesota in 1993 just before the Web, gopher was a
widely successful method of making menus of material available over the
Internet.
Gopher was
designed to be much easier to use than FTP, while still
using a text-only interface.
Gopher is
a Client and Server style program,
whichrequires that the user have a Gopher Client program.
Although Gopher spread rapidly across the globe in only a couple of years, it
has been largely supplanted by Hypertext, also known as WWW (World Wide
Web). There are
still thousands of Gopher Servers on the Internet
and we can expect they will remain for a while.
As used in
reference to the World Wide Web, ?hit? means a single request from a
web browser for a single
item from a web server; thus in order
for a web browser to display a page that contains 3 graphics, 4 ?hits? would
occur at the server: 1 for the HTML page, and one
for each of the 3 graphics.
Several
meanings. Originally, the web page that
your browser is set to use
when it starts up. The more common meaning refers to the main web page for a
business, organization, person or simply the main page out of a collection of
web pages, e.g. "Check out so-and-so's new Home Page."
Any computer on
a network that is a
repository for services available to other computers on the network. It is quite
common to have one host machine provide several services, such as SMTP (email)
and HTTP(web).
HTML -- (HyperText
Markup Language)
The coding
language used to create Hypertext documents for
use on the World Wide
Web. HTML looks a
lot like old-fashioned typesetting code, where you surround a block of text with
codes that indicate how it should appear.
The
"hyper" in Hypertext comes from the fact that in HTML you can specify that a
block of text, or an image, is linked to another file on the Internet. HTML
files are meant to be viewed using a "Web Browser".
HTML is
loosely based on a more comprehensive system for markup called SGML, and is
expected to eventually be replaced by XML-based XHTML standards.
HTTP -- (HyperText
Transfer Protocol)
The protocol
for moving hypertextfiles across
the Internet. Requires a
HTTP client program on one
end, and an HTTP server program (such
as Apache) on the other
end. HTTP is the most important protocol used in the World Wide Web
(WWW).
Generally, any
text that contains links to other documents - words or phrases in the document
that can be chosen by a reader and which cause another document to be retrieved
and displayed.
IMAP -- (Internet
Message Access Protocol)
IMAP is
gradually replacing POP as the main
protocol used by email clients in
communicating with email servers.
Using IMAP an
email client program can not only retrieve email but can also manipulate message
stored on the server, without having to actually retrieve the messages. So
messages can be deleted, have their status changed, multiple mail boxes can be
managed, etc.
IMAP is defined
in RFC 2060
Any time you
connect 2 or more networks together, you
have an internet - as in inter-national or inter-state.
The vast
collection of inter-connected networks that are connected using the TCP/IP protocols and
that evolved from the ARPANET of the late
60's and early 70's.
The Internet
connects tens of thousands of independent networks into a vast
global internet and is probably
the largest Wide Area
Network in the
world.
A
private network inside a
company or organization that uses the same kinds of software that you would find
on the public Internet, but that is
only for internal use. Compare with extranet.
IP
Number -- (Internet
Protocol Number)
Sometimes
called a dotted quad. A unique number consisting of 4 parts separated by dots,
e.g.
165.113.245.2
Every machine
that is on the Internet has a unique IP number - if a machine does not have an
IP number, it is not really on the Internet. Many machines (especially servers)
also have one or more Domain Names that are easier for people to
remember.
IPv4 -- (Internet
Protocol, version 4)
The most widley
used version of the Internet Protocol (the "IP" part of TCP/IP.)
IPv4
allows for a theoretical maximum of approximately four billion IP
Numbers (technically
232), but the actual number is far less due to inefficiencies in the
way blocks of numbers are handled by networks. The gradual adoption
of IPv6 will solve this
problem.
IPv6 -- (Internet
Protocol, version 6)
The successor
to IPv4. Already
deployed in some cases and gradually spreading, IPv6 provides a huge number of
available IP
Numbers - over a
sextillion addresses (theoretically 2128). IPv6 allows every device
on the planet to have its own IP Number.
IRC -- (Internet
Relay Chat)
Basically a
huge multi-user live chat facility. There are a number of major IRC servers around the
world which are linked to each other. Anyone can create a channel and anything
that anyone types in a given channel is seen by all others in the channel.
Private channels can (and are) created for multi-person conference
calls.
ISDN -- (Integrated
Services Digital Network)
Basically a way
to move more dataover existing regular phone lines. ISDN is available to much of
the USA and in most markets it is priced very comparably to standard analog
phone circuits. It can provide speeds of roughly 128,000 bits-per-second over
regular phone lines. In practice, most people will be limited to 56,000or 64,000
bits-per-second.
Unlike DSL, ISDN can be
used to connect to many different locations, one at a time, just like a regular
telephone call, as long the other location also has
ISDN.
ISP -- (Internet
Service Provider)
An institution
that provides access to the Internet in some form, usually for
money.
IT -- (Information
Technology)
A very general
term referring to the entire field of Information Technology - anything from
computer hardware to programming to network management. Most medium and large
size companies have IT Departments.
Java is a
network-friendly programming language invented by Sun Microsystems.
Java is
often used to build large, complex systems that involve several different
computers interacting across networks, for example transaction processing
systems.
Java is
also used to create software with graphical user interfaces such as editors,
audio players, web browsers, etc.
Java is
also popular for creating programs that run in small electronic devicws, such as
mobile telephones.
Using
small Java programs (called "Applets"), Web pages can include functions
such as animations,calculators, and other fancy tricks.
JavaScript is a
programming language that is mostly used in web pages, usually to add features
that make the web page more interactive. When JavaScript is included in
an HTML file it relies
upon the browser to interpret the JavaScript. When JavaScript is combined
with Cascading Style
Sheets(CSS), and
later versions of HTML (4.0 and later) the result is often called DHTML.
JDK -- (Java
Development Kit)
A software
development package from Sun Microsystems that implements the basic set of tools
needed to write, test and debugJava applications
and applets
JPEG -- (Joint
Photographic Experts Group)
JPEG is most
commonly mentioned as a format for image files. JPEG format is preferred to
the GIF format for
photographic images as opposed to line art or simple logo
art.
A thousand
bytes. Actually, usually 1024 (210) bytes.
LAN -- (Local Area
Network)
A computer
network limited to the immediate area, usually the same building or floor of a
building.
A widely used
Open Source Unix-like operating system. Linux was first released by its inventor
Linus Torvalds in 1991. There are versions of Linux for almost every available
type of computer hardware from desktop machines to IBM mainframes. The inner
workings of Linux are open and available for anyone to examine and change as
long as they make their changes available to the public. This has resulted in
thousands of people working on various aspects of Linux and adaptation of Linux
for a huge variety of purposes, from servers to TV-recording
boxes.
Noun or a
verb.
Noun: The
account name used to gain access to a computer system. Not a secret (contrast
with Password).
Verb: the act
of connecting to a computer system by giving your credentials (usually your
"username" and "password")
MIME --
(Multipurpose Internet Mail Extensions)
Originally a
standard for defining the types of files attached to standard Internet mail
messages. The MIME standard has come to be used in many situations where one
cmputer programs needs to communicate with another program about what kind of
file is being sent.
For
example, HTML files have a
MIME-type of text/html, JPEG files
are image/jpeg,
etc.
Modem -- (MOdulator,
DEModulator)
A device that
connects a computer to a phone line. A telephone for a computer. A modem allows
a computer to talk to other computers through the phone system. Basically,
modems do for computers what a telephone does for humans.
The maximum
practical bandwidth using a modem
over regular telephone lines is currently around 57,000 bps.
The
first WWW
browser that was
available for the Macintosh, Windows,and UNIX all with the same interface.
Mosaic really started the popularity of the Web. The source-code to Mosaic was
licensed by several companies and used to create many other web
browsers.
Mosaic was
developed at the National Center for Supercomputing Applications (NCSA), at the
University of Illinois in Urbana-Champaign, in Illinois, USA. The first version
was released in late 1993.
The etiquette
on the Internet.
A WWW
Browser and the name of
a company. The Netscape (tm) browser was originally based on the Mosaic program
developed at the National Center for Supercomputing Applications
(NCSA).
Any time you
connect 2 or more computers together so that they can share resources, you have
a computer network. Connect 2 or more networks together and you have
an internet.
NNTP -- (Network
News Transport Protocol)
The protocol
used by clientand server software to
carry USENET postings back
and forth over a TCP/IP network. If you are
using any of the more common software such as Netscape, Nuntius,
Internet Explorer, etc. to participate in newsgroups then you are
benefiting from an NNTP connection.
Any single
computer connected to a network.
Open Source
Software is software for which the underlying programming code is available to
the users so that they may read it, make changes to it, and build new versions
of the software incorporating their changes. There are many types of Open Source
Software, mainly differing in the licensing term under which (altered) copies of
the source code may (or must be) redistributed.
The method used
to move data around on the Internet. In packet
switching, all the data coming out of a machine is broken up into chunks, each
chunk has the address of where it came from and where it is going. This enables
chunks of data from many different sources to co-mingle on the same lines, and
be sorted and directed along different routes by special machines along the way.
This way many people can use the same lines at the same
time.
You might think
of several caravans of trucks all using the same road system to carry
materials.
A code used to
gain access (login) to a locked system. Good passwords contain letters
and non-letters and are not simple combinations such as virtue7. A good
password might be:
5%df(29)
But don't use
that one!
PDF -- (Portable
Document Format)
A file format
designed to enable printing and viewing of documents with all their formatting
(typefaces, images, layout, etc.) appearing the same regardless of what
operating system is used, so a PDF document should look the same on Windows,
Macintosh, linux, OS/2, etc. The PDF format is based on the widely used
Postcript document-description language. Both PDF and Postscript were developed
by the Adobe Corporation.
Perl -- (Practical
Extraction and Report Language)
Perl is a
programming language that is widely used for both very simple, small tasks and
for very large complex applications.
During
the 1990s it became the de-facto standard for creating CGI programs. Perl
is known for providing many ways to accomplish the same task, with "there's more
than one way to do it" being something of a motto in the Perl
community.
Because
it is so easy to perform simple tasks in Perl it is often used by people with
little or no formal programming training, and because Perl provides many
sophisticated features it is often used by professionals for creating complex
data-processing software, including the "server-side" of
large web
sites. Perl does not
provide significant support for creating programs with a graphical user
interface.
PHP -- (PHP:
Hypertext Preprocessor)
PHP is a
programming language used almost exclusively for creating software that is part
of a web
site. The PHP
language is designed to be intermingled with the HTML that is used to
create web
pages. Unlike HTML,
the PHP code is read and processed by the web server software (HTML
is read and processed by the web browser software.)
To check if a
server is running. From the sound that a sonar systems makes in movies, you
know, when they are searching for a submarine.
A (usually
small) piece of software that adds features to a larger piece of software.
Common examples are plug-ins for the Netscape® browser and
web server. Adobe
Photoshop® also uses plug-ins.
PNG -- (Portable
Network Graphics)
PNG is a
graphics format specifically designed for use on the World Wide Web. PNG enable
compression of images without any loss of quality, including high-resolution
images. Another important feature of PNG is that anyone may create software that
works with PNG images without paying any fees - the PNG standard is free of any
licensing costs.
POP -- (Point of
Presence, also Post Office Protocol)
Two commonly
used meanings:
Point of Presence and Post Office
Protocol.
A Point of
Presence usually means a city or location where a network can be connected to,
often with dial up phone lines. So if an Internet company says they will soon
have a POP in Belgrade, it means that they will soon have a local phone number
in Belgrade and/or a place where leased lines can connect to their
network.
A second
meaning, Post Office Protocol refers to a way that e-mail client software such
as Eudora gets mail from a mail server. When you
obtain an account from an Internet Service Provider (ISP) you almost
always get a POP account with it, and it is this POP account that you tell your
e-mail software to use to get your mail. Another protocol called IMAP is
replacing POP for email.
3 meanings.
First and most generally, a place where information goes into or out of a
computer, or both. E.g. the serial port on a personal computer is where
a modem would be
connected.
On the Internet
port often refers to a number that is part of a URL, appearing after a colon (:)
right after the domain name. Every service on an Internet server listens on a
particular port number on that server. Most services have standard port numbers,
e.g. Web servers normally listen on port 80. Services can also listen on
non-standard ports, in which case the port number must be specified in a URL
when accessing the server, so you might see a URL of the
form:
gopher://peg.cwis.uci.edu:7000/
This shows a
gopher server running on a non-standard port (the standard gopher port is
70).
Finally, port
also refers to translating a piece of software to bring it from one type of
computer system to another, e.g. to translate a Windows program so that is will
run on a Macintosh.
PPP -- (Point to
Point Protocol)
The most common
protocol used to connect home computers to the Internet over regular phone
lines.
Most well known
as a protocol that allows a computer to use a regular telephone line and
a modem to
make TCP/IPconnections and
thus be really and truly on the Internet.
On the Internet
"protocol" usually refers to a set of rules that define an exact format for
communication between systems. For example the HTTP protocol
defines the format for communication between web browsers and web servers,
the IMAP protocol
defines the format for communication between IMAP email servers and clients, and
the SSL protocol
defines a format for encrypted communications over the Internet.
Virtually
all Internet protocls are defined in RFC documents.
See
also: FTP, HTTP, IMAP, POP, PPP, RFC, SLIP, SMTP, SNMP, SSL, TCP/IP, UDP
A Proxy Server
sits in between a Client and the
"real" Server that a Client
is trying to use. Client's are sometimes configured to use a Proxy Server,
usually an HTTP server. The
clients makes all of it's requests from the Proxy Server, which then makes
requests from the "real" server and passes the result back to the Client.
Sometimes the Proxy server will store the results and give a stored result
instead of making a new one (to reduce use of a Network). Proxy
servers are commonly established on Local Area
Networks
A
special-purpose computer (or software package) that handles the connection
between 2 or more Packet-Switched networks. Routers spend
all their time looking at the source and destination addresses of
thepackets passing through
them and deciding which route to send them on.
RSS -- (Rich Site
Summary or RDF Site Summary or Real Simple Syndication)
A commonly used
protocol for syndication and sharing of content, originally developed to
facilitate the syndication of news articles, now widely used to share the
contents of blogs. Mashups are often made
using RSS feeds.
RSS is
an XML-based summary
of a web site, usually used for syndication and other kinds of
content-sharing.
There
are RSS "feeds" which are sources of RSS information about web sites, and RSS
"readers" which read RSS feeds and display their content to users.
RSS is
being overtaken by a newer, more complex protocol called Atom.
A (usually
web-based) system for searching the information available on the Web.
Some search
engines work by automatically searching the contents of other systems and
creating a database of the results. Other search engines contains only material
manually approved for inclusion in a database, and some combine the two
approaches.
SEO -- (Search
Engine Optimization)
The practice of
designing web pages so that they rank as high as possible in search results
from search
engines.
There
is "good" SEO and "bad" SEO. Good SEO involves making the web page clearly
describe its subject, making sure it contains truly useful information,
including accurate information in Meta
tags, and arranging
for other web sites to make links to the page. Bad SEO involves attempting to
deceive people into believing the page is more relevant than it truly is by
doing things like adding inaccurate Meta tags to the
page.
A computer, or
a software package, that provides a specific kind of service to client software
running on other computers. The term can refer to a particular piece of
software, such as a WWW server, or to
the machine on which the software is running, e.g. "Our mail server is down
today, that's why e-mail isn't getting out."
A single server
machine can (and often does) have several different server software packages
running on it, thus providing many different servers to clients on
the network.
Sometimes
server software is designed so that additional capabilities can be added to the
main program by adding small programs known as servlets.
SMTP -- (Simple Mail
Transfer Protocol)
The main
protocol used to send electronic mail from server to server on
the Internet.
SMTP is defined
in RFC 821 and
modified by many later RFC's.
An
inappropriate attempt to use a mailing
list,
or USENET or other
networked communications facility as if it was a broadcast medium (which it is
not) by sending the same message to a large number of people who didn?t ask for
it. The term probably comes from a famous Monty Python skit which featured the
word spam repeated over and over. The term may also have come from someone?s low
opinion of the food product with the same name, which is generally perceived as
a generic content-free waste of resources. (Spam® is a registered trademark of
Hormel Corporation, for its processed meat product.)
A somewhat
vague term generally referring to software that is secretly installed on a users
computer and that monitors use of the computer in some way without the users'
knowledge or consent.
Most
spyware tries to get the user to view advertising and/or particular web
pages. Some spyware
also sends information about the user to another machine over the
Internet.
Spyware
is usually installed without a users' knowledge as part of the installation of
other software, especially software such as music sharing software obtained
via download.
SQL -- (Structured
Query Language)
A specialized
language for sending queries to databases. Most industrial-strength and many
smaller database applications can be addressed using SQL. Each specific
application will have its own slightly different version of SQL implementing
features unique to that application, but all SQL-capable databases support a
common subset of SQL.
A example of an
SQL statement is:
SELECT name,email FROM
people_table WHERE contry='uk'
The term "tag"
can be used as a noun or verb. As a noun, a tag is a basic element of the
languages used to create web pages (HTML) and similar languages such
as XML. Another, more
recent meaning of tag is related to reader-crearted tags where blogs and other
content (such as photos, music, etc.) may be "tagged" which means to assign a
keyword, such as "politics" or "gardening", this enables searches for "all the
blog postings in the past week that are tagged 'prenatal
care'"
TCP/IP --
(Transmission Control Protocol/Internet Protocol)
This is the
suite of protocols that defines the Internet. Originally
designed for the UNIX operating
system, TCP/IP software is now included with every major kind of computer
operating system. To be truly on theInternet, your computer must have
TCP/IP software.
A computer
program is either hidden inside another program or that masquerades as something
it is not in order to trick potential users into running it. For example a
program that appears to be a game or image file but in reality performs some
other function. The term "Trojan Horse" comes from a possibly mythical ruse of
war used by the Greeks sometime between 1500 and 1200
B.C.
A Trojan Horse
computer program may spread itself by sending copies of itself from the host
computer to other computers, but unlike a virus it will
(usually) not infect other programs.
UDP -- (User
Datagram Protocol)
One of the
protocols for data transfer that is part of the TCP/IP suite of
protocols. UDP is a "stateless" protocol in that UDP makes no provision for
acknowledgement of packets received.
A computer
operating system (the basic software running on a computer, underneath things
like word processors and spreadsheets). Unix is designed to be used by many
people at the same time (it is multi-user) and has TCP/IP built-in. It is
the most common operating system for servers on
the Internet.
Apple
computers' Macintosh operating system, as of version 10 ("Mac OS X"), is based
on Unix.
Transferring
data (usually a file) from a the computer you are using to another computer. The
opposite of download.
URL -- (Uniform
Resource Locator)
The term URL is
basically synonymous with URI. URI has
replaced URL in technical specifications.
A chunk of
computer programming code that makes copies of itself without any concious human
intervention. Some viruses do more than simply replicate themselves, they might
display messages, install other software or files, delete software of files,
etc.
A virus
requires the presence of some other program to replicate itself. Typically
viruses spread by attaching themselves to programs and in some cases files, for
example the file formats for Microsoft word processor and spreadsheet programs
allow the inclusion of programs called "macros" which can in some cases be a
breeding ground for viruses.
A specification
and various technologies used to allow making telephone calls over IP networks,
especially the Internet.
Just
as modems allow computers
to connect to the Internet over regular telephone lines, VOIP technology allows
humans to talk over Internet connections.
Costs for VOIP calls can be a
lot lower than for traditional telephone calls. Because the IP networks
are packet-switched this allows for
vastly different ways of handling connections and more efficient use of network
resources.
VPN -- (Virtual
Private Network)
Usually refers
to a network in which some
of the parts are connected using the public Internet, but the data
sent across the Internet is encrypted, so the entire network is "virtually"
private.
WAN -- (Wide Area
Network)
Any internet or network that covers an
area larger than a single building or campus.
Short for
"World Wide Web."
A document
designed for viewing in a web browser. Typically
written in HTML. A web
site is made of one
or more web pages.
The entire
collection of web
pages and other
information (such as images, sound, and video files, etc.) that are made
available through what appears to users as a single web server. Typically all
the of pages in a web site share the same basic URL, for example
the following URLs are all for pages within the same web
site:
http://www.baytherapy.com/
http://www.baytherapy.com/whatis/
http://www.baytherapy.com/teenagers/
The term has a
somewhat informal nature since a large organization might have separate "web
sites" for each division, but someone might talk informally about the
organizations' "web site" when speaking of all of them.
Wi-Fi -- (Wireless
Fidelity)
A popular term
for a form of wireless data communication, basically Wi-Fi is "Wireless
Ethernet".
A wiki is a web
site for which the content can be easily edited and altered from the web browser
in which you are viewing it. Typically there is an "edit" button on each page
and the wiki is configured to allow either anyone or only people with passwords
to edit each page. The word "wiki" comes from a Hawaiian word meaning
"quick."
A worm is
a virus that does not
infect other programs. It makes copies of itself, and infects additional
computers (typically by making use of network connections) but does not attach
itself to additional programs; however a worm might alter, install, or destroy
files and programs.
World Wide Web
(or simply Web for short) is a term frequently used (incorrectly) when referring
to "The Internet", WWW has two major meanings:
First, loosely
used: the whole constellation of resources that can be accessed
using Gopher, FTP,
HTTP,telnet, USENET, WAIS and some other
tools.
Second, the
universe of hypertext servers (HTTP
servers), more commonly
called "web servers", which are the servers that serve web
pages to
web browsers.
XHTML -- (eXtensible
HyperText Markup Language)
Basically HTML expressed as
valid XML. XHTML is
intended to be used in the same places you would use HTML (creating web pages)
but is much more strictly defined, which makes it a lot easier to create sofware
that can read it, edit it, check it for errors, etc.
XHTML
is expected to eventually replace HTML.
XML -- (eXtensible
Markup Language)
A widely used
system for defining data formats. XML provides a very rich system to define
complex documents and data structures such as invoices, molecular data, news
feeds, glossaries, inventory descriptions, real estate properties,
etc.
As long
as a programmer has the XML definition for a collection of data (often called a
"schema") then they can create a program to reliably process any data formatted
according to those rules.
XML is
a subset of the older SGML specification -
the definition of XML is SGML minus a couple of dozen
items.
