Authentication, authorization, and access control

Before I focus on the different methods of access control and how access control is managed, I want to step back and explain how access is actually granted to a resource—how you, a service, or an application (essentially, any identity), gain the access and permission. I will also explain the access control methods used to carry out the actions that are required.

Authentication

At a high level, when an identity has to gain access to a resource or an environment (for example, a user logging in to an AWS account), the user has to identify itself in the form of a username, and then verify that they are who they say they are, which is normally confirmed in the form of a password...