When creating a package, the first thing you will have to answer is if the package is a credit package. Credits are used as class passes/ tokens to be able to book into events in your calendar.
A credit package is basically used as a 'top up' service. It is a package that doesn't recur and doesn't have an expiry date, however for purchasing purposes can be bought over and over again without any restrictions.
If a client purchases a credit package and it has 1 credit, that credit will stay in their account until it is used and they can keep buying the package as and when they need to top up their credits.
A regular package can have an expiry date which means that when the package expires anything in the package will expire with it, it can also be recurring for subscription purposes and it can also be set to not expire which means that the package will remain in the clients profile unless cancelled.
You can also add assignments to a regular package such as programs, workouts, nutrition plans, files and client groups.
A regular package can also have credits added to it, these can recur with a recurring package or be set to expire or not expire. If the package hasn't expired yet or wasn't set to expire then the client will not be able to purchase this again until it has expired or been cancelled within their profile.