What is a paid database?

Lite Database A Lite database is database software offered for free and contains a limited selection of functionality. It will work forever but more advanced features are disabled. This is done to allow people to 'try before the buy'.

Paid Database

A Paid version offers all of the functionality but at a cost.

Trial Database

A Trial version offers all of the functionality of the Paid database, but only for a short period of time. Generally a month or less. After that point, it either offers Lite database functionality or none at all.

Open Source

Databases that are fully functional and free to use forever.

In general, these types refer not to the database itself or it's abilities, but to the methods of driving sales of the database software.