Cloud Identity
Cloud Identity is Google Cloud's main service for identity management. It is an IDaaS solution that gives developers a unified platform to manage all of their members (users and groups). These users can even be your team members' personal Gmail accounts, which you can use to grant them access. This would not be possible without Cloud Identity.
In essence, it is an authentication tool that verifies the identities of users – it does not assign them the roles. It only checks if they are eligible for access and that authorization is still done by the IAM policy, as shown in the following diagram:
Cloud Identity is also, in a way, cross-platform as it allows you to use identities between Google Cloud and other cloud vendors that have their own identity services: AWS and Azure. However, this isn't something we will be discussing as we will...