There are majorly 3 IAM Identities available
IAM Users
IAM Groups
IAM Role
Let's see more about these
IAM Identities are what you create under your AWS account to provide authentication for people, applications, and processes in your AWS account.
Identities represent the user and can be authenticated and then authorized to perform actions in AWS
Each of these can be associated with one or more policies to determine what actions a user, role, or member of a group can do with which resources and under what conditions.
The IAM group is a collection of IAM users.
IAM role is very similar to IAM user.