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A BASIC GUIDE
TO THE INTERNET
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.
COMPONENTS OF THE INTERNET
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.
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 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.
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