Glossary
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[W] [X] [Y] [Z]
ActiveX
This set of technologies from Microsoft provides tools for linking desktop
applications to the World Wide Web. Using a variety of programming
tools--including Java, Visual Basic, and C++--developers can
create interactive Web content. For instance, ActiveX technology
can allow users to view Word and Excel documents directly
in a browser.
ADSL
(Asymmetric Digital Subscriber Line)
A method
for moving data over regular phone lines. This type of circuit
is much faster than a regular telephone connection, and the
wires into the subscriber's premises are the same (copper)
wires used for regular phone service. It has been discussed
as an alternative to ISDN, allowing higher speeds.
Applet
A small
Java program that can be embedded in an HTML page.
ARPANet
(Advanced Research Projects Agency Network)
The forerunner
to the Internet. Developed in the late 60's and early 70's
by the US Department of Defence as an experiment in wide-area-networking
that would survive a nuclear war.
ASCII
(American Standard Code for Information Interchange)
This is
the 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.
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Backbone
A high-speed
line or series of connections that forms a major pathway within
a network.
Bandwidth
How much
material you can send through a connection. Usually measured
in bits-per-second. A full page of English text is about 16,000
bits. A fast modem can move about 15,000 bits in one second.
Full-motion full-screen video would require roughly 10,000,000
bits-per-second, depending on compression.
Baud
In common
usage the baud rate 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).
BBS (Bulletin
Board System)
A computerised
meeting and announcement system that allows people to carry
on discussions, upload and download files, and make announcements
without the people being connected to the computer at the
same time. There is an immense number of BBS¹s around the
world; most are very small, running on a single PC with 1
or 2 phone lines.
Binhex
(Binary Hexadecimal)
A method
for converting non-text files (non-ASCII) into ASCII. This
is needed because Internet e-mail can only handle ASCII.
Bit (Binary
DigIT)
A single
digit number in base-2, in other words, either a 1 or a zero.
The smallest unit of computerised data. Bandwidth is usually
measured in bits-per-second. See Also: Bandwidth, Bps, Byte,
Kilobyte, and Megabyte
BITNET
A network
of educational sites separate from the Internet, but e-mail
is freely exchanged between BITNET and the Internet.
Bps (Bits-Per-Second)
A measurement
of how fast data is moved from one place to another. A 28.8
modem can move 28,800 bits per second.
Browser
A Client
program (software) that is used to look at various kinds of
Internet resources.
Byte
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.
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CSS
Cascading
Style Sheets are a big breakthrough in Web design because
they allow delvelopers to control the style and layout of
multiple Web pages all at once. Before Cascading Style Sheets,
changing an element that appeared on many pages required changing
it on each individual page. Cascading Style Sheets work just
like a template, allowing Web developers to define a style
for an HTML element and then apply it to as many Web pages
as they'd like. With CSS, when you want to make a change,
you simply change the style, and that element is updated automatically
wherever it appears within the site. Both Navigator 4.0 and
Internet Explorer 4.0 support Cascading Style Sheets. If you
needed any more proof of the problem-solving nature of CSS,
the World Wide Web Consortium (W3C) has recommended Cascading
Style Sheets (level 1) as an industry standard.
Certificate
Authority
An issuer
of Security Certificates used in SSL connections.
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.
Cgi-bin
The most
common name of a directory on a web server in which CGI programs
are stored. The 'bin' part of 'cgi-bin' is a shorthand version
of 'binary', because once upon a time, most programs were
referred to as 'binaries'.
Client
A software
program that is used to contact and obtain data from a Server
software program on another computer, often across a great
distance. Each Client 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.
Co-location
Most often
used to refer to having a server that belongs to one person
or group physically located on an Internet-connected network
that belongs to another person or group. Usually this is done
because the server owner wants their machine to be on a high-speed
Internet connection and/or they do not want the security risks
of having the server on their own network.
Cookie
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 Browser¹s 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 customise what is sent back
to the user, or keep a log of particular user's 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 but they can be used to gather
more information about a user than would be possible without
them.
Cyberspace
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.
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DHTML
Dynamic HTML combines HTML, style sheets, and scripts to make Web pages
more interactive. It sounds great. But while both Microsoft
Internet Explorer 4.0 and Netscape Communicator 4.0 support
dynamic HTML features, they do so in different--and incompatible--ways.
The companies say they will work to make their browsers compatible
with whatever specification the W3C finally decides upon.
However, the browsers may be in their fifth generation before
users see a concrete standard.
Domain
Name
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. Domain
Names. 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.
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E-mail
(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 (Mailing List).
Ethernet
A very
common method of networking computers in a LAN. Ethernet will
handle about 10,000,000 bits-per-second and can be used with
almost any kind of computer.
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FAQ (Frequently
Asked Questions)
FAQs are
documents that list and answer the most common questions on
a particular subject. There are hundreds of FAQs on subjects
as diverse as Pet Grooming and Cryptography. People who have
tired of answering the same question over and over usually
write FAQs.
FDDI (Fibre
Distributed Data Interface)
A standard
for transmitting data on optical fibre cables at a rate of
around 100,000,000 bits-per-second (10 times as fast as Ethernet,
about twice as fast as T-3).
Finger
An Internet
software tool for locating people on other Internet sites.
Finger is also sometimes used to give access to non-personal
information, but the most common use is to see if a person
has an account at a particular Internet site. Many sites do
not allow incoming Finger requests, but many do.
Fire Wall
A combination
of hardware and software that separates a LAN into two or
more parts for security purposes.
Some organisations
have chosen to separate their networks from the rest of the
world while still allowing certain users the ability to access
resources outside of that organisation's network. This access
is provided through a "gateway" or "firewall"
host system and is generally uni-directional.
There are
other kinds of firewall, which are not specifically configured.
If your local area network is behind a router-based firewall
or behind a gateway requiring passive transfers, use the Passive
mode of FTP.
FTP (File
Transfer Protocol)
A very
common method of moving files between two Internet sites.
FTP is a special 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.
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Gateway
The technical
meaning is a hardware or software set-up that translates between
two dissimilar protocols, for example Prodigy 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 colour. 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.
Gigabyte
1000 or
1024 Megabytes, depending on whom is measuring.
Gopher
A widely
successful method of making menus of material available over
the Internet. Gopher is a Client and Server style program,
which requires 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
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Hit
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. 'Hits' are
often used as a very rough measure of load on a server, e.g.
'Our server has been getting 300,000 hits per month.' Because
each 'hit' can represent anything from a request for a tiny
document (or even a request for a missing document) all the
way to a request that requires some significant extra processing
(such as a complex search request), the actual load on a machine
from 1 hit is almost impossible to define.
Home Page
(or Homepage)
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, organisation, person or simply the main page out
of a collection of web pages,
Host
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 WWW and
USENET.
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, additionally, in HTML you can specify
that a block of text, or a word, is linked to another file
on the Internet.
HTML 3.0
This extension of Hypertext Markup Language expands the original HTML
specification, which was pretty basic and allowed documents
to contain only one column of text, a little formatting, and
a few graphics. Developed by the World Wide Web Consortium
and Web software developers, HTML 3.0 offers enhanced graphics
capabilities and enables Web-page designers to put in tables
and frames and to flow text around figures. To read documents
written in HTML 3.0 you must have a browser that supports
it.
HTTP (HyperText
Transfer Protocol)
The protocol
for moving hypertext files across the Internet. Requires a
HTTP client program on one end, and an HTTP server program
on the other end. HTTP is the most important protocol used
in the World Wide Web (WWW).
Hypertext
Hypertext is a nonsequential way of presenting information. Hypertext
links information in a complex web of associations, powered
by hyperlinks. Essentially a way of browsing information,
hypertext is a way to describe how you learn information from
a well-designed CD-ROM encyclopedia or from the World Wide
Web.
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Internet
address
An Internet
address or IP address is a unique identifier that defines
a system's location on the Internet network. IP addresses
are 32-bit addresses that are commonly specified in Internet
dot notation, which consists of four numbers from 1 to 255
separated by dots (.), for example: 156.21.50.1
Each IP
address is mapped to a unique hostname, as it is easier for
people to remember names than it is to remember strings of
numbers.
Internet
(Upper case I)
The vast
collection of inter-connected networks that all use the TCP/IP
protocols and that evolved from the ARPANET of the late 60's
and early 70's.
internet
(Lower case i)
Any time
you connect 2 or more networks together, you have an internet
- as in inter-national
Intranet
A private
network inside a company or organisation that uses the same
kinds of software that you would find on the public Internet,
but that is only for internal use. As the Internet has become
more popular many of the tools used on the Internet are being
used in private networks; for example, many companies have
web servers that are available only to employees. Note that
an Intranet may not actually be an Internet, it may simply
be a network.
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.
Most machines also have one or more Domain Names that are
easier for people to remember.
ISDN (Integrated
Services Digital Network)
Basically
a way to move more data over existing regular phone lines.
ISDN can provide speeds of upto 128,000 bits-per-second over
regular phone lines. In practice, most people will be limited
to 56,000 or 64,000 bits-per-second.
ISP (Internet
Service Provider)
A company
that provides access to the Internet.
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Java
Sun Microsystems' Java is a programming language for adding animation
and other action to Web sites. The small applications (called
applets) that Java creates can play back on any graphical
system that's Web-ready, but your Web browser has to be Java-capable
for you to see it. According to Sun's description, Java is
a "simple, object-oriented, distributed, interpreted,
robust, secure, architecture-neutral, portable, high-performance,
multithreaded, dynamic, buzzword-compliant, general-purpose
programming language.".
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.
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Kilobyte
One thousand
bytes. Actually, usually 1024 (2^10) bytes.
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LAN (Local
Area Network)
A computer
network limited to the immediate area, usually the same building
or floor of a building.
Leased-line
Refers
to a phone line that is rented for exclusive 24-hour, 7 -days-a-week
use from your location to another location. The highest speed
data connections require a leased line. See Also: T-1, T-3
Listserv®
The most
common kind of maillist, "Listserv" is a registered
trademark of L-Soft international, Inc. Listserv's originated
on BITNET but they are now common on the Internet.
Login
- The
account name used to gain access to a computer system. Not
a secret (contrast with Password).
- The
act of entering into a computer system.
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Maillist
(or Mailing List)
A (usually
automated) system that allows people to send e-mail to one
address, whereupon their message is copied and sent to all
of the other subscribers to the maillist. In this way, people
who have many different kinds of e-mail access can participate
in discussions together.
Megabyte
One million
bytes. Actually, technically, 1024 kilobytes.
MIME (Multipurpose
Internet Mail Extensions)
The standard
for attaching non-text files to standard Internet mail messages.
Non-text files include graphics, spreadsheets, formatted word-processor
documents, sound files, etc.
An email
program is said to be MIME Compliant if it can both send and
receive files using the MIME standard.
When non-text
files are sent using the MIME standard they are converted
(encoded) into text - although the resulting text is not really
readable.
Mirror
Generally
speaking, 'to mirror' is to maintain an exact copy of something.
Probably the most common use of the term on the Internet refers
to 'mirror sites' which are web sites, or FTP sites that maintain
exact copies of material originated at another location, usually
in order to provide more widespread access to the resource.
Another
common use of the term 'mirror' refers to an arrangement where
information is written to more than one hard disk simultaneously,
so that if one disk fails, the computer keeps on working without
losing anything.
Modem
(MOdulator, DEModulator)
A device
that you connect to your computer and to a phone line, that
allows the computer to talk to other computers through the
phone system. Basically, modems do for computers what a telephone
does for humans.
Mosaic
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.
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Netiquette
The etiquette
on the Internet.
Netscape
A WWW
Browser and the name of a company.
Network
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.
Newsgroup
The name
for discussion groups.
NIC (Networked
Information Centre)
Generally,
any office that handles information for a network. The most
famous of these on the Internet is the InterNIC, which is
where new domain names are registered. Another definition:
NIC also refers to Network Interface Card, which plugs into
a computer and adapts the network interface to the appropriate
standard. ISA, PCI, and PCMCIA cards are all examples of NICs.
NNTP (Network
News Transport Protocol)
The protocol
used by client and 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.
Node
Any single
computer connected to a network.
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Packet
Switching
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 to different routes by special machines along the
way. This way many people can use the same lines at the same
time.
Password
A code
used to gain access to a locked system. Good passwords contain
letters and non-letters and are not simple combinations such
as virtue7. A good password might be: Sad£2-6
Plug-in
A (usually
small) piece of software that adds features to a larger piece
of software. Common examples are plug-ins for the Adobe Photoshop®.
The idea
behind plug-IN's is that a small piece of software is loaded
into memory by the larger program, adding a new feature, and
that users need only install the few plug-ins that they need,
out of a much larger pool of possibilities.
POP (Point
of Presence, also 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.
- Post
Office Protocol refers to the way e-mail software such as
Eudora gets mail from a mail server. When you obtain a SLIP,
PPP, or shell account 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.
Port
- 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.
- 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.
See Also: Domain Name, Server, and URL.
Portal
Usually
used as a marketing term to described a Web site that is or
is intended to be the first place people see when using the
Web. Typically a "Portal site" has a catalogue of
web sites, a search engine, or both. A Portal site may also
offer email and other service to entice people to use that
site as their main "point of entry" (hence "portal")
to the Web.
Posting
A single
message entered into a network communications system.
E.g. A
single message posted to a newsgroup or message board.
PPP (Point
to Point Protocol)
Most well
known as a protocol that allows a computer to use a regular
telephone line and a modem to make TCP/IP connections and
thus be really and truly on the Internet.
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Router
A special-purpose
computer (or software package) that handles the connection
between 2 or more networks. Routers spend all their time looking
at the destination addresses of the packets passing through
them and deciding which route to send them on.
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Security
Certificate
A chunk
of information (often stored as a text file) that is used
by the SSL protocol to establish a secure connection.
Security
Certificates contain information about who it belongs to,
who it was issued by, a unique serial number or other unique
identification, valid dates, and an encrypted 'fingerprint'
that can be used to verify the contents of the certificate.
In order
for an SSL connection to be created both sides must have a
valid Security Certificate.
Server
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 isn¹t getting
out. A single server machine could have several different
server software packages running on it, thus providing many
different servers to clients on the network.
SMTP (Simple
Mail Transfer Protocol)
The main
protocol used to send electronic mail on the Internet.
SMTP consists
of a set of rules for how a program sending mail and a program
receiving mail should interact.
Almost
all Internet email is sent and received by clients and servers
using SMTP, thus if one wanted to set up an email server on
the Internet one would look for email server software that
supports SMTP.
SNMP (Simple
Network Management Protocol)
A set
of standards for communication with devices connected to a
TCP/IP network. Examples of these devices include routers,
hubs, and switches.
Spam (or
Spamming)
An inappropriate
attempt to use a mailing list, or USENET or other networked
communications facility as if it was a broadcast medium by
sending the same message to a large number of people who didn't
request it.
SQL (Structured
Query Language)
A specialised
programming 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 version of SQL implementing features unique to
that application, but all SQL-capable databases support a
common subset of SQL.
SSL (Secure
Sockets Layer)
A protocol
designed by Netscape Communications to enable encrypted, authenticated
communications across the Internet.
SSL used
mostly (but not exclusively) in communications between web
browsers and web servers. URL's that begin with 'https' indicate
that an SSL connection will be used.
SSL provides
3 important things: Privacy, Authentication, and Message Integrity.
In an SSL
connection each side of the connection must have a Security
Certificate, which each side¹s software sends to the other.
Each side then encrypts what it sends using information from
both its own and the other side¹s Certificate, ensuring that
only the intended recipient can de-crypt it, and that the
other side can be sure the data came from the place it claims
to have come from, and that the message has not been tampered
with.
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T-1
A leased-line
connection capable of carrying data at 1,544,000 bits-per-second.
At maximum theoretical capacity, a T-1 line could move a megabyte
in less than 10 seconds. That is still not fast enough for
full-screen, full-motion video, for which you need at least
10,000,000 bits-per-second. T-1 is the fastest speed commonly
used to connect networks to the Internet. See Also: Bandwidth,
Bit, Byte, Ethernet, and T-3
T-3
A leased-line
connection capable of carrying data at 44,736,000 bits-per-second.
This is more than enough to do full-screen, full-motion video.
See Also: Bandwidth, Bit, Byte, Ethernet, and T-1
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 available for every major kind of computer operating system.
To be truly on the Internet, your computer must have TCP/IP
software.
Telnet
The command
and program used to login from one Internet site to another.
The telnet command/program gets you to the login: prompt of
another host.
Terabyte
1000 gigabytes.
Terminal
A device
that allows you to send commands to a computer somewhere else.
At a minimum, this usually means a keyboard and a display
screen and some simple circuitry. Usually you will use terminal
software in a personal computer - the software pretends to
be (emulates) a physical terminal and allows you to type commands
to a computer somewhere else.
Terminal
Server
A special
purpose computer that has places to plug in many modems on
one side and a connection to a LAN or host machine on the
other side. Thus the terminal server does the work of answering
the calls and passes the connections on to the appropriate
node. Most terminal servers can provide PPP or SLIP services
if connected to the Internet.
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UNIX
A computer
operating system (the basic software running on a computer,
underneath things likes 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.
URL (Uniform
Resource Locator)
The standard
way to give the address of any resource on the Internet that
is part of the World Wide Web (WWW). A URL looks like this:
http://www.matisse.net/seminars.html or telnet://well.sf.ca.us
or news:new.newusers.questions etc. The most common way to
use a URL is to enter into a WWW browser program, such as
Netscape, or Lynx.
UUENCODE
(Unix to Unix Encoding)
A method
for converting files from Binary to ASCII (text) so that they
can be sent across the Internet via e-mail.
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WAIS (Wide
Area Information Servers)
A commercial
software package that allows the indexing of huge quantities
of information, and then making those indices searchable across
networks such as the Internet. A prominent feature of WAIS
is that the search results are ranked (scored) according to
how relevant the hits are, and that subsequent searches can
find more stuff like that last batch and thus refine the search
process.
WAN (Wide
Area Network)
Any internet
or network that covers an area larger than a single building
or campus.
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