On the Internet, a domain is basically a registration category identifying geographic or purpose commonality. On the Internet, domains are arranged in a hierarchical tree structure and there are seven top-level domains currently in use:

com - A commercial organization. The largest domain extension currently used
edu - An educational establishment such as a school or university
gov - A branch of the U.S government that is strictly reserved for that purpose
int - An international organization such as the United Nations
net - A network organization
org - A non-profit organization
mil - A branch of the U.S military that is strictly reserved for that purpose

In other parts of the world the final part of the domain name represents the country in which the server is located like bb for Barbados, ca for Canada and uk for Great Britain.

Path

The path portion of the URL refers to the path on the host that the resource can be found. Given the following URL, http://www.PetShop.com/test/index.htm, the resource can be can in the subdirectory called test on the www.PetShop.com Web server.

The path portion of the URL can be one or more than one directory.

http://www.PetShop.com/test/index.htm

Resource name

The last part of the URL is the actual name of the resource that is being requested from the server. This is usually an HTML or HTM file that can be downloaded and displayed in your Web browser.

http://www.PetShop.com/test/index.htm