In Google Cloud IAM, what is the fundamental difference between a primitive role (like Editor) and a predefined role (like Compute Instance Admin)?

Primitive roles can only be assigned to Service Accounts.

Primitive roles grant broad permissions across all services in a project, while predefined roles grant granular permissions for specific services.

Predefined roles are created by users, while primitive roles are created by Google.

Primitive roles are free, while predefined roles incur a monthly charge.