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A Technical Overview of the World Wide Web
There are essentially three components which together form the
World Wide Web, the mediumwhich has brought this document to your
screen. They are the Internet , the Information Servers which
contain and dispense information, and the Web Browser which the
individual uses to
obtain information and pages from the web. This page briefly
describes each of thesecomponents.
The quick explaination of the web is this: web browsers use the
Internet to access Servers thatcontain the pages, images, and other
files that the web user is interested in receiving. See our
page on Client/Server Software Architecture to find out more
about the relationship between programs like browsers (referred to
as "clients") and servers.
The Internet
The Internet, on the technological level, consists of the wires,
cables, machines, and networking
software which connects millions of computers around the world.
This complex infrastructure ofcomputer networks is the pavement of
the "Information Superhighway" that allows web
browsers to communicate with servers, request, send, and receive
information from around theworld, regardless of global
location.
Information Servers
Information servers run on computers connected to the Internet
all over the world. Informationservers are processes (executing
computer software) which dish out information as requestedfrom
users connected to the same network (in the case of the WWW, the
public Internet). Themost common information types of servers on
the Internet today are:
World Wide Web servers; also called http servers for the
underlying protocol with which they communicate withWeb browsers ,
the H yper T ext T ransport P rotocol. These servers primarily
deliver datafor immediate human consumption, primarily web pages.
WebCom allows people to havetheir own websites by giving people the
abiliity to create pages that are served byWebCom's World Wide Web
servers. See also: hypertext and multimedia .
Gopher servers; the immediate predecessors of World Wide Web
servers, gopher servers present files indistributed archives to you
as hierarchical menus. Using a gopher client , you would selecta
file from a menu. If that file were text, it would next appear on
your screen for you to
read or browse. If it were any other form of data, such as an
image, the file would betransferred to your local computer where
you would have to use a separate program toview or use it. After
you were done reading or downloading a file, a gopher client
wouldalways return you to the previous menu from which you had
selected the file.
FTP, or File Transport Protocol Servers; whose only function is
to allow FTP clients to copy files of any kind (programs,
images,text, etc.) between the client and server machines. FTP
allows you to enter commandsand filenames to send to, receive from,
and otherwise manage files and directories on a
http://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/glossary/client_server.shtmlhttp://www.webcom.com/glossary/client_server.shtmlhttp://www.webcom.com/glossary/client_server.shtmlhttp://www.webcom.com/glossary/server.shtmlhttp://www.webcom.com/glossary/server.shtmlhttp://www.webcom.com/glossary/server.shtmlhttp://www.webcom.com/glossary/browser.shtmlhttp://www.webcom.com/glossary/browser.shtmlhttp://www.webcom.com/glossary/browser.shtmlhttp://www.webcom.com/http://www.webcom.com/http://www.webcom.com/http://www.webcom.com/glossary/hypertext.shtmlhttp://www.webcom.com/glossary/hypertext.shtmlhttp://www.webcom.com/glossary/hypertext.shtmlhttp://www.webcom.com/glossary/multimedia.shtmlhttp://www.webcom.com/glossary/multimedia.shtmlhttp://www.webcom.com/glossary/multimedia.shtmlhttp://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/help/ftphttp://www.webcom.com/help/ftphttp://www.webcom.com/help/ftphttp://www.webcom.com/help/ftphttp://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/glossary/multimedia.shtmlhttp://www.webcom.com/glossary/hypertext.shtmlhttp://www.webcom.com/http://www.webcom.com/glossary/browser.shtmlhttp://www.webcom.com/glossary/server.shtmlhttp://www.webcom.com/glossary/client_server.shtmlhttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#INTERhttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#BROWShttp://www.webcom.com/help/overview/www.shtml#SERVEhttp://www.webcom.com/help/overview/www.shtml#INTER
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remote computer. (If you log in to read files other than your
own, you have to log in as"anonymous" or "ftp", which allows you to
read all public files but not alter or deletethem, or create new
ones.) When you retrieve a file from a remote computer using
FTP,you have to invoke a separate program after your FTP session to
view that file (a texteditor, an image viewer, etc.). WebCom
customers use FTP to maintain their WebCom
file directories. Graphical FTP clients for Windows or Macintosh
relieve the user of theneed to learn most of the FTP commands,
allowing the user instead to simply drag anddrop files to and from
their WebCom directory as though it were a local drive on
theirmachine.
NNTP, or Network News Transport Protocol servers; which deliver
Usenet newsgroups and articles.
SMTP, Simple Mail Transport Protocol servers; which send and
receive electronic mail messages.
Archie; which searches indices of FTP archives for files when
given a file name or namefragment.
Veronica; which searches gopher menus for words or
phrases.Telnet servers;
which allow you to login and conduct a terminal session on the
remote computer runningthe server from anywhere on the net. These
sessions are normally UNIX terminalsessions conducted via "VT100"
terminal emulators - programs that allow your computerto emulate a
DEC VT100 terminal to the remote host.
WAIS, Wide Area Information Servers; which search distributed
volumes of text (which have been pre-indexed for this purpose)for
words and phrases, and rank results based on a score - how closely
each documentsatisfied the search criterion.
In the past, accessing these servers required using a separate
program for each server type. Toaccess a gopher server, you had to
run a gopher client program. To access an FTP server, youhad to run
your FTP client. To search for a file using Archie or Veronica, you
had to run eitheran Archie or a Veronica client.
Web Browsers
The third component of the World Wide Web, a new generation of
Internet information clients called Web Browsers, such as Mosaic
and Lynx have recently been developed. These browsershave three new
capabilities which revolutionize searching and browsing the
Internet:
1. World Wide Web browsers are multilingual; they can
communicate with all of theservers listed above and more. This
relieves the user of the complexities of having tolearn and run a
separate client for each server they wish to use. There is still
some valueto understanding the functionality of the underlying
servers, however this is less of arequirement when using a WWW
browser. Also, for some of these servers it is oftenmore convenient
to use a specialized client, such as a threaded news reader to
readUsenet news, an Email program to send and receive Email
messages, or an FTP client
http://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/glossary/client.shtmlhttp://www.webcom.com/glossary/mosaic.shtmlhttp://www.webcom.com/glossary/mosaic.shtmlhttp://www.webcom.com/glossary/mosaic.shtmlhttp://www.webcom.com/glossary/lynx.shtmlhttp://www.webcom.com/glossary/lynx.shtmlhttp://www.webcom.com/glossary/lynx.shtmlhttp://www.webcom.com/glossary/news_reader.shtmlhttp://www.webcom.com/glossary/news_reader.shtmlhttp://www.webcom.com/glossary/news_reader.shtmlhttp://www.webcom.com/glossary/news_reader.shtmlhttp://www.webcom.com/glossary/lynx.shtmlhttp://www.webcom.com/glossary/mosaic.shtmlhttp://www.webcom.com/glossary/client.shtml
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when, for instance, you want to send a file from your computer
to a remote computer, oryou want to retrieve a large number of
files in one bulk copy operation.
2. World Wide Web browsers employ a graphical user interface.
Many of the above serversrequire you to learn an arcane command
language or enter UNIX commands. With aWWW browser, you just use
your mouse or arrow keys to point at what you want, and
click or press return. The browser takes care of the underlying
network communications,interfaces, and commands, to bring to you
what you clicked on.3. WWW browsers allow the free-form
organization and cross linking and referencing of
information called hypertext, hypermedia, or hyperlinking. In
this form of informationorganization, any item of information (a
word, a phrase, an image) can also function as a"hotlink " to any
other item of information. Underneath every hotlink, hidden to
thereader, is a URL, or Uniform Resource Locator, which tells your
browser where to findthe resource pointed to by that hotlink; all
you do is point and click. Furthermore,anybody can create hotlinks
in their documents to any other publicly accessible resource(you
can create hotlinks to your own resources or anybody elses, and
anybody else cancreate hotlinks to your information). This
structure creates freedom to organize and share
information in myriad and novel ways, resulting in an anarchic,
loosely structured web ofinformation, art, music, data, software,
literature, and just about anything else which can be represented
in digital form and which some person or organization has a desire
toshare with the world. This is the World Wide Web.
As World Wide Web browsers greatly simplify the browsing and
retrieval information from theWeb, we at WebCom aim to greatly
simplify your ability to be a provider of information andservices
on the Web.
http://www.webcom.com/glossary/link.shtmlhttp://www.webcom.com/glossary/link.shtmlhttp://www.webcom.com/glossary/link.shtmlhttp://www.webcom.com/info/http://www.webcom.com/info/http://www.webcom.com/info/http://www.webcom.com/info/http://www.webcom.com/glossary/link.shtml
