sites that may contain relevant content and provide links to those sites.  Search engines

and directories often return a limited number of sites in their search results (e.g., the

Google search engine will return only 2,000 sites in response to a search, even if it has

found, for example, 530,000 sites in its index that meet the search criteria). 

A user may also access content on the Web by typing a URL (Uniform Resource

Locator) into the address line of the browser.  A URL is an address that points to some

resource located on a Web server that is accessible over the Internet.  This resource may

be a Web site, a Web page, an image, a sound or video file, or other resource.  A URL

can be either a numeric Internet Protocol or  IP  address, or an alphanumeric  domain

name  address.  Every Web server connected to the Internet is assigned an IP address.  A

typical IP address looks like  13.1.64.14.   Typing the URL  http://13.1.64.14/  into a

browser will bring the user to the Web server that corresponds to that address.  For

convenience, most Web servers have alphanumeric domain name addresses in addition to

IP addresses.  For example, typing in  http://www.paed.uscourts.gov  will bring the user

to the same Web server as typing in  http://204.170.64.143.  

Every time a user attempts to access material located on a Web server by entering

a domain name address into a Web browser, a request is made to a Domain Name Server,

which is a directory of domain names and IP addresses, to  resolve,  or translate, the

domain name address into an IP address.  That IP address is then used to locate the Web

server from which content is being requested.  A Web site may be accessed by using

either its domain name address or its IP address. 

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