What means the web address?

The web address is what you are going to write in the URL search.
In a web address there are important informations about the web site.
For example:
http://www.cnn.com

http stands for HyperText Tranfer Protocol and is the language, or protocol, used for displaying Web pages.
www stands for World Wide Web which is the worldwide network that the computers connect to the internet communicate.
cnn is the name of the site
com it indicates the type of the network

Sometimes after the http, may appear a 's' which stands for security.