The Internet is a computer network made up of thousands of networks
worldwide. No one knows exactly how many computers are connected to the
Internet. It is certain, however, that these number in the millions.
No one is in charge of the Internet. There are organizations which
develop technical aspects of this network and set standards for creating
applications on it, but no governing body is in control. The Internet
backbone, through which Internet traffic flows, is owned by private
companies.
All computers on the Internet communicate with one another using the
Transmission Control Protocol/Internet Protocol suite, abbreviated to
TCP/IP. Computers on the Internet use a client/server architecture. This
means that the remote server machine provides files and services to the
user's local client machine. Software can be installed on a client
computer to take advantage of the latest access technology.
An Internet user has access to a wide variety of services: electronic
mail, file transfer, vast information resources, interest group
membership, interactive collaboration, multimedia displays, real-time
broadcasting, shopping opportunities, breaking news, and much more.
The Internet consists primarily of a variety of access protocols. Many
of these protocols feature programs that allow users to search for and
retrieve material made available by the protocol.
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COMPONENTS OF THE INTERNET
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WORLD WIDE WEB
The World Wide Web (abbreviated as the Web or WWW) is a system of
Internet servers that supports hypertext to access several Internet
protocols on a single interface. Almost every protocol type available on
the Internet is accessible on the Web. This includes e-mail, FTP,
Telnet, and Usenet News. In addition to these, the World Wide Web has
its own protocol: HyperText Transfer Protocol, or HTTP. These protocols
will be explained later in this document.
The World Wide Web provides a single interface for accessing all these
protocols. This creates a convenient and user-friendly environment. It
is no longer necessary to be conversant in these protocols within
separate, command-level environments. The Web gathers together these
protocols into a single system. Because of this feature, and because of
the Web's ability to work with multimedia and advanced programming
languages, the Web is the fastest-growing component of the Internet.
The operation of the Web relies primarily on hypertext as its means of
information retrieval. HyperText is a document containing words that
connect to other documents. These words are called links and are
selectable by the user. A single hypertext document can contain links to
many documents. In the context of the Web, words or graphics may serve
as links to other documents, images, video, and sound. Links may or may
not follow a logical path, as each connection is programmed by the
creator of the source document. Overall, the Web contains a complex
virtual web of connections among a vast number of documents, graphics,
videos, and sounds.
Producing hypertext for the Web is accomplished by creating documents
with a language called HyperText Markup Language, or HTML. With HTML,
tags are placed within the text to accomplish document formatting,
visual features such as font size, italics and bold, and the creation of
hypertext links. Graphics and multimedia may also be incorporated into
an HTML document. HTML is an evolving language, with new tags being
added as each upgrade of the language is developed and released. The
World Wide Web Consortium (W3C), led by Web founder Tim Berners-Lee,
coordinates the efforts of standardizing HTML. The W3C now calls the
language XHTML and considers it to be an application of the XML language
standard.
The World Wide Web consists of files, called pages or home pages,
containing links to documents and resources throughout the Internet.
The Web provides a vast array of experiences including multimedia
presentations, real-time collaboration, interactive pages, radio and
television broadcasts, and the automatic "push" of information to a
client computer. Programming languages such as Java, JavaScript, Visual
Basic, Cold Fusion and XML are extending the capabilities of the Web. A
growing amount of information on the Web is served dynamically from
content stored in databases. The Web is therefore not a fixed entity,
but one that is in a constant state of development and flux.
For more complete information about the World Wide Web, see Understanding The World Wide Web.
E-MAIL
Electronic mail, or e-mail, allows computer users locally and worldwide
to exchange messages. Each user of e-mail has a mailbox address to which
messages are sent. Messages sent through e-mail can arrive within a
matter of seconds.
A powerful aspect of e-mail is the option to send electronic files to a
person's e-mail address. Non-ASCII files, known as binary files, may be
attached to e-mail messages. These files are referred to as MIME
attachments.MIME stands for Multimedia Internet Mail Extension, and was
developed to help e-mail software handle a variety of file types. For
example, a document created in Microsoft Word can be attached to an
e-mail message and retrieved by the recipient with the appropriate
e-mail program. Many e-mail programs, including Eudora, Netscape
Messenger, and Microsoft Outlook, offer the ability to read files
written in HTML, which is itself a MIME type.
TELNET
Telnet is a program that allows you to log into computers on the
Internet and use online databases, library catalogs, chat services, and
more. There are no graphics in Telnet sessions, just text. To Telnet to a
computer, you must know its address. This can consist of words
(locis.loc.gov) or numbers (140.147.254.3). Some services require you to
connect to a specific port on the remote computer. In this case, type
the port number after the Internet address. Example: telnet
nri.reston.va.us 185.
Telnet is available on the World Wide Web. Probably the most common
Web-based resources available through Telnet have been library catalogs,
though most catalogs have since migrated to the Web. A link to a Telnet
resource may look like any other link, but it will launch a Telnet
session to make the connection. A Telnet program must be installed on
your local computer and configured to your Web browser in order to work.
With the increasing popularity of the Web, Telnet has become less
frequently used as a means of access to information on the Internet.
FTP
FTP stands for File Transfer Protocol. This is both a program and the
method used to transfer files between computers. Anonymous FTP is an
option that allows users to transfer files from thousands of host
computers on the Internet to their personal computer account. FTP sites
contain books, articles, software, games, images, sounds, multimedia,
course work, data sets, and more.
If your computer is directly connected to the Internet via an Ethernet
cable, you can use one of several PC software programs, such as WS_FTP
for Windows, to conduct a file transfer.
FTP transfers can be performed on the World Wide Web without the need
for special software. In this case, the Web browser will suffice.
Whenever you download software from a Web site to your local machine,
you are using FTP. You can also retrieve FTP files via search engines
such as FtpFind, located at /http://www.ftpfind.com/. This option is
easiest because you do not need to know FTP program commands.
E-MAIL DISCUSSION GROUPS
One of the benefits of the Internet is the opportunity it offers to
people worldwide to communicate via e-mail. The Internet is home to a
large community of individuals who carry out active discussions
organized around topic-oriented forums distributed by e-mail. These are
administered by software programs. Probably the most common program is
the listserv.
A great variety of topics are covered by listservs, many of them
academic in nature. When you subscribe to a listserv, messages from
other subscribers are automatically sent to your electronic mailbox. You
subscribe to a listserv by sending an e-mail message to a computer
program called a listserver. Listservers are located on computer
networks throughout the world. This program handles subscription
information and distributes messages to and from subscribers. You must
have a e-mail account to participate in a listserv discussion group.
Visit Tile.net at /http://tile.net/ to see an example of a site that
offers a searchablecollection of e-mail discussion groups.
Majordomo and Listproc are two other programs that administer e-mail
discussion groups. The commands for subscribing to and managing your
list memberships are similar to those of listserv.
USENET NEWS
Usenet News is a global electronic bulletin board system in which
millions of computer users exchange information on a vast range of
topics. The major difference between Usenet News and e-mail discussion
groups is the fact that Usenet messages are stored on central computers,
and users must connect to these computers to read or download the
messages posted to these groups. This is distinct from e-mail
distribution, in which messages arrive in the electronic mailboxes of
each list member.
Usenet itself is a set of machines that exchanges messages, or articles,
from Usenet discussion forums, called newsgroups. Usenet administrators
control their own sites, and decide which (if any) newsgroups to
sponsor and which remote newsgroups to allow into the system.
There are thousands of Usenet newsgroups in existence. While many are
academic in nature, numerous newsgroups are organized around
recreational topics. Much serious computer-related work takes place in
Usenet discussions. A small number of e-mail discussion groups also
exist as Usenet newsgroups.
The Usenet newsfeed can be read by a variety of newsreader software
programs. For example, the Netscape suite comes with a newsreader
program called Messenger. Newsreaders are also available as standalone
products.
FAQ, RFC, FYI
FAQ stands for Frequently Asked Questions. These are periodic postings
to Usenet newsgroups that contain a wealth of information related to the
topic of the newsgroup. Many FAQs are quite extensive. FAQs are
available by subscribing to individual Usenet newsgroups. A Web-based
collection of FAQ resources has been collected by The Internet FAQ
Consortium and is available at /http://www.faqs.org/.
RFC stands for Request for Comments. These are documents created by and
distributed to the Internet community to help define the nuts and bolts
of the Internet. They contain both technical specifications and general
information.
FYI stands for For Your Information. These notes are a subset of RFCs and contain information of interest to new Internet users.
Links to indexes of all three of these information resources are
available on the University Libraries Web site at
/http://library.albany.edu/reference/faqs.html.
CHAT & INSTANT MESSENGING
Chat programs allow users on the Internet to communicate with each other
by typing in real time. They are sometimes included as a feature of a
Web site, where users can log into the "chat room" to exchange comments
and information about the topics addressed on the site. Chat may take
other, more wide-ranging forms. For example, America Online is well
known for sponsoring a number of topical chat rooms.
Internet Relay Chat (IRC) is a service through which participants can
communicate to each other on hundreds of channels. These channels are
usually based on specific topics. While many topics are frivolous,
substantive conversations are also taking place. To access IRC, you must
use an IRC software program.
A variation of chat is the phenomenon of instant messenging. With
instant messenging, a user on the Web can contact another user currently
logged in and type a conversation. Most famous is America Online's
Instant Messenger. ICQ, MSN and Yahoo are other commonly-used chat
programs.
Other types of real-time communication are addressed in the tutorial Understanding the World Wide Web.
MUD/MUSH/MOO/MUCK/DUM/MUSE
MUD stands for Multi User Dimension. MUDs, and their variations listed
above, are multi-user virtual reality games based on simulated worlds.
Traditionally text based, graphical MUDs now exist. There are MUDs of
all kinds on the Internet, and many can be joined free of charge. For
more information, read one of the FAQs devoted to MUDs available at the
FAQ site at
