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.
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.
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