How to use trust policies with IAM roles | AWS Security Blog

Authentication using SAML2.0 federation – This is commonly used by enterprises with Active Directory that want to connect using an IAM role so that their users can use single sign-on workflows to access AWS accounts. In all cases, the makeup of an IAM role is the same as that of an IAM user and is only differentiated by the following qualities:

https://aws.amazon.com/blogs/security/how-to-use-trust-policies-with-iam-roles/