Prospect / Lead - These are contacts that are future paying customers, those who have expressed interest.
On a Trial - They are contacts that have purchased a trial membership.
Formerly On a Trial - They were on a trial, and did not enroll in a longer term membership.
Students / Members / Customers / Clients - These are active paying customers.
Inactive Students / Members / Customers /Clients - They are no longer an active customer, but if they have memberships or payments that are still due in the future, they will still be collected upon.
Former - Same as inactive, except the automatic payments will not be collected upon.
Vendor / Supplier - Contacts that you buy products and services from.
Business - Instead of being an individual, these are tracked as a business.
Other - Contacts that do not fit into the above categories.