AWS IAM Explained in 60 Seconds

Key Takeaways

Before we launch servers or databases, we need to talk about security. IAM stands for identity and access management and it controls who can do what inside your AWS account. Think of IAM like the bouncer at the door. Every person and every service must show ID before they can get in. If you're logging in as a human, IAM gives you a user account. You can group users together like admins, developers, or finance and assign permissions using policies. A policy is just a JSON document that says things like allow this user to access S3, block this user from deleting EC2 instances, allow read-only access to CloudWatch logs. Policies are the rule book. Users and groups follow those rules. Now, here's the part that matters the most. IAM roles. Roles are like temporary permission jackets that AWS services can wear. For example, our EC2 instance needs permission to upload images to S3, our Lambda function needs permission to read from S3 and write to the database. CloudWatch needs permission to collect logs. None of these services use usernames or passwords. They get permissions by assuming an IAM role. This is why IAM comes early in our architecture. When we launch EC2 in the next lesson, the first thing we'll do is attach an IAM role to it. That role will decide whether our back end can actually talk to S3 or RDS. Without IAM, all the other AWS services are basically locked doors.