What are the URL's Used in Internet?

Think of them as addresses.

Uniform Resource Locators (URLs) are used to identify documents (resources) on the Internet

General format of URL: scheme:object-address

• The scheme is often a communications protocol such as http,ftp,gopher,file,mailto,news..
• Different schemes use object addresses that have different forms.

For the HTTP protocol ,the object address of URL is fully_qualified_domain_name/path_to_document

For the file protocol, the object address of URL is file://path_to_document

URLs cannot include embedded spaces ,special characters like semicolons,colons,ampersands(&). To include space or disallowed special characters in URL ,character must be coded as a % followed by 2 digit hex ASCII code for the character.

ex: if San Jose is a domain name , then we must write San%20Jose.

URL paths differ form that of file path (which includes all directories on the path) -need not include all directories on the path that is URLs can have complete path or partial path.

complete path ex:

http://www.abc.com/files/f99/strore.html

partial paths: the path to the document is relative to some base path that is specified in the configuration files of the server.

ex: http:/www.abc.com/store.html

http:/www.abc.com

http:/www.abc.com/dept