# Principal permissions
<a name="Principalpermissions"></a>

When you use an IAM user or role to perform actions in AWS, you are considered a principal. Policies grant permissions to a principal. When you use some services, you might perform an action that then triggers another action in a different service. In this case, you must have permissions to perform both actions. To see whether an action requires additional dependent actions in a policy, see [Actions, Resources, and Condition Keys for AWS Documentation Essentials](https://docs.aws.amazon.com/service-authorization/latest/reference/reference.html) in the *Service Authorization Reference*.