Packages entail what a customer can purchase as a plan or an add-on bundle.
A product is the base object for creating charges on customers or offering services to customers. Products can be one-time fees, resource grantors, recurring fees, or service products.
Discounts are objects with a set of rules and rule filters that determine what the discount targets exactly.
Event generators generate a usage event based on a pre-defined mapper at billing time, just before the bill is moved into the billing status.