Authentication, Authorization, and Accounting or AAA is an framework that allows access to a computer network/resource,
Authentication
Authentication identifies the user. It’s from the Greek authentikos “real, genuine”. We can think of it as proving the identity of the user. Bob sits down at the computer and types in his password (Something he knows) and confirms that he is in fact Bob.
Authorization
Authorization is the privileges that the user has to the system. For instance, Bob is now authenticated to the computer, but he may only be authorized to access email and a web browser.
Authorization and Authentication can get confusing. In simple terms
- Authentication – Who are you?
- Authorization – What you have access to.
Accounting
Accounting is the auditing or logging arm of AAA. It is for answering the 5 Ws Who did what, when, where, and how. For instance, accounting could log that Bob checked his email at 9:30AM, Improved his mind by reading posts on incredigeek.com for a couple hours, then checked email again before shutting the computer down.
Hopefully that is a short helpful explanation of AAA. For more information, check out the following links.
https://afteracademy.com/blog/authentication-vs-authorization/