SSL stands as secure socket layer, of the main protocol which is used to secure the data transmission. In this article I am trying to discuss how this SSL certificate is used in client server architecture. First of all you should know the difference of "Authentication" and "Authorization". Authentication means validate the correct user, for instance most of times when you tried to log to the system, it will ask user name and password to log it. That is called as authentication. Only user who is given correct user name and password allow to log to the system. When you log to a particular site what are the things you are allowed to do and not to do, in other words the privileges that you have in that site called as Authorization. These two concepts are used when client (your browser) requests from server through SSL protocol. You may wonder what is the reason of having such a system. This all about trust. Once you type your favorite site, www.facebook