AWS Identity and Access Management: Who Gets In?

IAM is the security guard of AWS. It controls who can access what. The biggest mistake I see beginners make is using the root user for everything. The root user has full access and should only be used to create the first admin user. After that, lock the root user away with multi-factor authentication. Create individual users for people or applications, and assign them permissions using groups. The principle of least privilege means giving only the permissions needed to do a job. IAM roles are even better for services that need permissions. It takes a little time to wrap your head around policies—they're JSON documents that define permissions—but mastering IAM is the key to keeping your AWS account secure.