AWS IAM Explained Without Making Your Head Hurt

AWS IAM Explained Without Making Your Head Hurt IAM (Identity and Access Management) is one of the most important services in AWS and one of the most confusing to learn. Here is a plain-language explanation. ## The Core Problem IAM Solves AWS gives you access to a lot of powerful services. Without access control, anyone with your credentials could do anything to your infrastructure. IAM is the system that controls who can do what. ## The Four Core Concepts Users A User is an identity representing a person or application. Users have credentials (password for console, access keys for API). In modern AWS setups, you should have as few IAM Users as possible. Human users should use SSO (Single Sign-On) or identity federation instead of IAM Users. Machines should use Roles. Groups A collection of Users. You assign permissions to Groups instead of individual Users when possible. This makes managing permissions for teams much easier. Roles A Role is like a User but with no permanent credential