User:
This is where the subscriber's details are.
First thing that's created when someone first signs into Connect
Where the user's personal details are kept, such as:
Name
Email address
Physical address
Date of birth
A user can have multiple subscriptions active
Subscription:
Holds the SIM and phone number, and is connected to a user and plan.
What the SIM and phone number are connected to
Only 1 SIM can be active on a subscription at a time
Can only have 1 plan active at a time
Plan:
The usage allotment, services (talk, text, data), and cost are determined with the plan.
Determines the:
Services that are available
The usage that's available
The frequency of the billing cycle
The cost per billing cycle