Correct Terminology of Types of Users and the Application Modules Built for Each

I'm designing a system that will have multiple modules. It is even possible that these modules are separated into different applications. Then it came a question I had previously asked myself but I could not get the answer:

What names should I give to different types of users of the modules of a system? Is there a current default pattern?

Existing example: Uber

Uber, with its "drivers users" and "passengers users", has an application for each of these types of users. Uber states that drivers are their partners and not employees (and not customers). But what about the passengers? Are they customers of Uber or customers of the drivers? Do you understand where I want to go?

My case:

In the case of my project, my client would be a number of different professionals who would be the source of money income for the system (so they would be my clients), and they would be users of a 'apk' module built only for them. These clients have their own clients, who would use another separate 'apk' module to use the services of the professionals already mentioned. These users (clients of my clients) would not pay to use the system. In addition, there are the users who administer my clients, using a CRM module that will be made for them.

In the end, there are at least 4 types of users:

• My customers
• Customers of my customers
• Employees of my customers, with more restricted access profile to work for my customers in the application
• Managers of my customers (my collaborators which have client wallets)

So, how should you name each module and its users? knowing that there is still the open module, which can be accessed without the need for authentication...

Dirty example:

1. Customers Module
2. Customers Clients Module + Public Areas Module
3. CRM Module