Understanding What URLs Do

Your browser's primary function is to locate pages on the Internet and display them for you. It is quite helpful to understand a few things about web the addresses or URLs that your browser uses to locate information on the web.

Server IP Numbers

Web pages don't float out in Internet space, they reside as files on servers. Each server has a number called an IP (Internet Protocol) number. If you enter the number below into the address field of your browser, it will find our San Mateo Community College District server.

Analyzing a URL
Every Web page has one or more URLs, which identify where it is located on the Web. URLs are used because they are easier to remember than numbers.
Protocol	Server Name	Domain	Directory(ies) on Server	Resource ID
			/ / / directories on server	files stored in subdirectory folder
http://	www.smccd	.net	/accounts/webreadyplus	/lesson11_web.asp
http://	www. pbs	.org	/marktwain/scrapbook/	/index.html
http://	www.cnn	.com	/TECH/	/index.html
http://	www.whitehouse	.gov	/homeland/	/index.html

Browsers will let you omit the http://

Server Name
The server name identifies the computer /server on which the web page or document file is found. This part of the URL commonly identifies which company, agency or organization may be either directly responsible for the information, or simply providing the computer space where the information is stored.
Server Name	Identifies company, agency or organization
www.smccd	San Mateo Community College District
www. pbs	Public Broadcasting System
www.cnn	Cable News Network
www.whitehouse	The White House

Domain Name
The server name always ends with a dot and a three-letter or two-letter extension called the domain name. The domain is important because it usually identifies the type of organization that created or sponsored the resource. Sometimes it indicates the country where the server is located. The most common domain names are:
	.com	identifies company or commercial sites
	.org	non-profit organization sites
	.edu	educational sites (most commonly four-year universities)
	.gov	government sites
	.net	Internet service providers or other types of networks
New Domain Names
	.aero	air transport industry
	.biz	businesses
	.coop	cooperatives
	.info	unrestricted use
	.name	individuals
	.museum	museums
	.pro	accountants, lawyers, physicians, and other professionals
New Top Level Domain names, http://www.internic.net/faqs/new-tlds.html ICANN "The Internet Corporation for Assigned Names and Numbers" http://www.icann.org/

Country Domains
If the domain name is two letters, it identifies a country. Each example below will lead you to the domain name registry in that country.
	.us	http://www.nic.us/
	.uk	http://www.nic.uk/
	.au	http://www.auda.org.au
	.mx	http://www.nic.mx
	.ca	http://www.cira.ca/
	.gr	http://www.gr/
Domain Name Registries Around the World, http://www.norid.no/domenenavnbaser/domreg.html

Directories
Subdirectories (folders) are created on a server to contain various types of related information. For example, for the course site,the subdirectory: /accounts/webreadyplus contain all the pages in the WebReadyPlus Web site.
Protocol	Server & Domain	Directory	Subdirectory	Files
		(folder)	(folder)	files stored in subdirectory folder
http://	www.smccd.net	/accounts	/WebReadyPlus	/lesson11.asp

Resource ID
The resource ID is the name of the file for the page which is stored on the specified server. The part of the resource ID after the last slash (/) is the file name for the specific page or other resource. The file name ends with a three or four letter designation: ( a few examples)
Directory	Resource ID
/ / / subdirectories	filename.rtf    filename.pdf (Adobe Acrobat)   filename .doc (Microsoft Word)    filename.gif filename .html or .asp         (Dreamweaver)
http://  www.smccd.net/  accounts/  webreadyplus/	lesson11_web.asp

 Continue!   

Main Pages	Current Lesson	Supporting Pages	Sub Topics
Lessons  (All)	L11 Internet Research	Understanding URLs
		Web Directories	General Directories
			Selected Subject Directories
		Directory Search Methods	Subject Searches
			Keyword Searches
			Boolean Quiz
		Search Engines	How They Work
			Selected Search Engines
			Search Strategies
			Web Page Evaluation Criteria
			Evaluations Form
			Practice

Centers for Teaching and Learning
Sevastopoulos, Bruni and Karas
Updated: 2/2003