Prince George's Community College

301 Largo Road
Largo, Maryland 20774

The Internet is composed of local, regional, national, and worldwide computer networks. Each computer on the Internet can be identified by a set of unique numbers that is called an Internet Protocol (IP) address. The IP address is composed of four different numbers separated by periods such as 205.134.120.60. While every computer has its own unique address, every user using the Internet has a unique address called a domain. A domain recognizes one or more IP addresses. An example of a domain is terrorism.com and is part of the URL such as http://www.terrorism.com/index.shtml. The standard top-level domains are:

• com - Commercial business
• edu - Educational institutions
• gov - Government agencies
• mil - Military
• net - Networks organization
• org - Organizations (nonprofit)

There are additional top-level domains that are now recognized on the Internet. They include:

• aero - Air-transport industry
• biz - Businesses
• coop - Cooperatives
• info - Unrestricted use
• museum - museums
• pro - Accountants, lawyers, physicians, and other professionals
• tv - Television

Some countries use a sub-domain or geographical domain as part of their address. Fox example, an academic institution such as Oxford University in the United Kingdom can use ac.uk. An example of a URL with this domain is http://www.ox.ac.uk/.

The Uniform Resource Locator (URL) is an addressing scheme that is used on the Internet to locate resources and/or services on the World Wide Web. Basically the URL is the address of a computer file that has been put on a computer server to access the Internet. An example of a URL and its components follow: Click on the image below to view this site.

To search the World Wide Web it is necessary to have a browser software loaded on a computer. Go to the next page of this module to learn about browsers.

A Brief History of the Internet
Hobbes' Internet Timeline
What is the Internet
What is the World Wide Web