Authorization is the question after the question. The user is who they say they are; what, then, are they allowed to read, write, or delete? The answer is, ideally, the smallest set that lets them do their work.
In plain language
In security, this is one of the pieces a system uses to keep the wrong people out and the right people in. Authorization is the question after the question. The user is who they say they are; what, then, are they allowed to read, write, or delete? The answer is, ideally, the smallest set that lets them do their work. If you are new to the field, the simplest mental model is this: deciding what an authenticated user may do. Read it once with that frame in mind, then come back and read it again — that is usually enough for the rest of the entry to make sense.
An everyday picture
Think of Authorization as a lock on a door. Boring when it works, suddenly the loudest thing in the room when it doesn't. The goal is for it to stay boring.
Where it shows up
Authorization runs in the background of any product that handles login, payment, or private data. It is most visible the moment it fails — someone gets in who shouldn't, or someone is locked out who shouldn't be.
A small example
Imagine the scene above. The role Authorization plays is the one its blurb describes — Deciding what an authenticated user may do. When you log in to a bank without anyone in a café reading your password, ideas like this are doing the protective work.
Common misunderstanding
One line to take with you
Authorization is a quiet promise. Keep the promise small, write it down, and check it works.