What is Authorization? Definition and explanations
Authorisation determines what an already-authenticated identity is allowed to do: which data to read, which actions to trigger, which records to modify. It is evaluated on every request, server side, and never merely by hiding a button in the interface. Broken access control tops the OWASP Top 10 precisely because that check is so often skipped.
In one sentence
Authorisation decides what an authenticated identity may do, on every request.