What is an IAM role?

What this card says

Why do we need it?

At Infosys Pune a visitor gets a time-bound pass for one floor — not a lifelong office badge. Compute needs the same pattern.

What is it?

An IAM role is an identity with no long-lived password or access key. A caller assumes it and STS returns temporary credentials.

AssumeRole

How to do it

Create the role, attach a permissions policy, set a trust policy for who may assume, then let EC2/Lambda/CLI assume it.

Example

An EC2 instance profile role lets the instance call S3 with rotating keys from the metadata service — no keys on disk.