AWS IAM: What is a role?

An IAM role is an identity you create to encapsulate a set of permissions that can then be assigned to different services, users, or applications.

Whereas user groups can only be assigned to IAM users, roles can be assigned to AWS services that need access to other AWS services. For example, you might assign a role to an AWS Lambda that gives it access to read from one of your DynamoDB tables.

Sources

• IAM roles – AWS docs