The "Internet" and the "World Wide Web" are not synonymous.  Although the two terms are often used interchangeably, they actually describe two discrete functions.  While the Internet acts as a facilitator for the exchange of information, the web itself contains merely one type of information which can be transported over the Net.

The web is a collection of interlinked documents written in a common format known as hypertext markup language, or HTML.  Individuals can use personal computers to gain access to the web via the Internet, by using clients known as web browsers.  The most common web browsers in use today are Netscape's Navigator and Microsoft's Internet Explorer.  A user can locate a particular HTML document, or web page, by entering its address, or URL, into the web browser.

A Uniform Resource Locator, or URL, consists of an Internet Protocol prefix, generally HTTP, and an Internet domain name, as well as any file or folder names which refer to a specific document location.  Take a moment to look at the URL for the current page.  The URL tells you that this page is in the "cyber.law.harvard.edu" domain, in the directory "property," in the folder "introtech," and that the name of the document itself is "webworks.html."

When an individual "calls up" a URL through his web browser, the web browser first has to resolve the address it has been given.  In this case, your web browser will first look for the computer which stores information on the ".edu" domain.  The domain name system is structured as a hierarchy of names, and .edu is what is referred to as a gTLD, a generic top level domain name.  A second level domain name consists of a top level domain name, with another name preceding it, separated by a dot.  For example, "harvard.edu" is a second level domain name.  The more "dots" which precede the top level domain name, the further the hierarchy is stretched.  In the case of the fourth level domain name "cyber.law.harvard.edu", your browser will first "ask" the computer containing the ".edu" registry where "harvard" can be found.  Having located "harvard," the browser will ask the directory at "harvard" where "law" can be found, and so on, until it reaches the location you have requested.   The browser then requests this information from the computer on which it is stored, and the information is sent back to the web browser, which displays it on your screen.

In addition to entering a URL directly into a web browser, search engines and directories are available to assist individuals in sorting through the millions of web pages accessible from the web.  The very popular Yahoo! is an example of a web directory.  Common search engines include AltaVista, Excite, and WebCrawler, among others.  There are also search engines designed to search for information on specific topics, such as GOVBOT which searches for government documents, and there are search engines designed to search multiple search engines at once, sometimes called "meta-searchers".

Search engines use several methods for obtaining information on particular sites on the web.  One of the most common tools is the use of a spider which "crawls" across the web recording incidences of search terms occurring in documents.  This information, in turn, assists search engine administrators in classifying documents.  No two search engines are likely to produce identical results for the same search query because of the differing methods employed by administrators in gathering and classifying information about specific web sites.
 

Created by Jocelyn R. Dabeau
Feedback?  Mail to: jdabeau
Last modified 2-22-99