When you sign up for a new Unified Management account, an account is created with a unique organization ID. The Organization Account follows the below organization structure. P1 has full access to all the organizational resources and P4 has the least access.
As the signed-up user is the first user of the Organization Account, the Super Admin role is assigned to the signed-up user by the default and then the assigned Super Admin can assign the Super Admin role to other employees up to 4. For more information, refer to Assigning a Super Admin Role.