difference between authentication and authorization in asp.net

authentication is taking the credentials like username and password and allow him to access the application
authorization is allowing a person to access a page after authentication.It can be set in the webconfig file.

uthentication is to verify that indentity has right to 
access or not

mechanisums are
1.windows
 for windows authentication we need iis because iis provid 
windows authentication.
2.passport 
in that authentication check using microsoft passport 
service.
3.form
in that authentication is based on session cokkies.if that 
is not available then page is redirected.

Authorization is the process to validate a user based on 
cridential