Authentication verifies a user's identity by having them log in, while authorization determines which resources and pages the authenticated user has access to. For example, after authenticating normal and admin users on a website, authorization would prevent normal users from accessing admin pages. Authentication occurs before authorization and verifies the user, even if anonymously, while authorization checks the user's access rights after identity is confirmed.

1. Difference between Authentication and Authorization in ASP.NET
S.No Authentication Authorization
1 Meaning: Meaning:
Authentication is the process of Authorization is process of checking
verifying the identity of a user. whether the user has access rights to
the system.
2 Example: Example:
Suppose, we have 2 types of users Once we know the user is valid, then
( normal and admins ) to a we determine to which pages the user
website. When the user tries to has access to. Normal users should not
access the website, we ask them to be able to access admin pages. This is
log in. This is authentication part. authorization part.
3 Types of Authentication: Types of Authorization:
Windows Authentication ACL authorization (also known as file
Forms Authentication authorization)
Passport Authentication URL authorization
4 Whent it takes place ? Whent it takes place ?
Authentication always precedes to Authorization takes place after
Authorization,event if our Authentication
application lets anonymous users
connect and use the application,it
still authenticates them as
anonymous.
And, further updates on difference between questions and answers, please visit my blog @
http://onlydifferencefaqs.blogspot.in/