Domain Names and Addresses

Each node on the Internet has a numeric address called its IP address. Additionally most sites also have a name called the fully qualified domain name.
These names are usually 3 or 4 strings separated by dots (periods). The names are associated with numerical IP (Internet Protocol) addresses

        Domain Name                     IP Address 
        www.mwc.edu                 	192.65.245.76
        nssdca.gfsc.nasa.gov            128.183.10.4
        askhp.ask.uni-karlsruhe.de      192.67.194.33

These domain names are used as part of an e-mail address and also used to access Internet services and resources.

To send electronic mail to someone you need to know their Internet address.
For nodes that are directly connected to the Internet this address is usually login-name@domain-name

To access an Internet service or resource you usually start a program, for example, a Web browser such as Netscape Navigator, and give the address of a remote site or service that will interact with the program you start.

Access to Internet services and resources is specified as a URL or Uniform Resource Locator. Two examples are
gopher://twinbrook.cis.uab.edu
http://www.webliminal.com/lrn-net.html

Be careful that the names you type are correct in terms of upper or lower case of letters, spelling, and punctuation.

The most general form of a URL is
service://doman-name-of-site-supplying-service/full-path-name-of-item

Client-Server