Authentication->Simple Login Form..(chek user if you r there or not) Authorization->Role Base System(Check you are admin or client.if you are admin you can assess data which u r allocated to use... and ....if u r user.you can access only ur page ..which permission given By admin:)

Please refer to the following link to know the differences between authentication and authorization,http://onlydifferencefaqs.blogspot.in/2012/08/difference-between-authentication-and.html

Authentication is something to check whether the user is right person or not. Authorisation is something which provides boundary of user's access.

Authentication is a process of verify the user and Authorization of process of verifying whether the authorised user is allowed to access the resource or not.