What is URL describe theri protocol?

URL basicallt stands for uniform resource locator. A URL is a pointer to a particular resource on the Internet at a particular location.

A URL specifies the protocol used to access a server (e.g., ftp, http), the name of the server, and the location of a file on that server. This specifies that there is a file called books.html in a directory called javafaq on the server metalab.unc.edu, and that this file can be accessed through the http protocol. The full syntax is:

protocol://hostname[:port]/path/filename#fragmentID

The protocol, also sometimes called the scheme, is generally one of these
file : a file on your local disk
ftp : an FTP server
http : a World Wide Web server
https : an HTTP server accessed over SSL
gopher : a Gopher server
mailto : an email address
news : a Usenet newsgroup
telnet : a connection to a Telnet-based service