## The concept is very simple:
You supply the customers and the product plans of your business.
You subscribe your customers to a plan.
Upodi charges according to your product plan and creates the invoices.
## Upodi definition of a subscription:
A subscription inherits the terms form the product plan and all the charges (products) available to the subscriber. A product plan can contain numerous of different charges with different pricing models and billing cycles, where a subscriber might only buy some of the charges available.