A picklist is a dropdown list that provides users with a list of valid values to select from. Filtered picklists contain more complexity and reference other lists in a model: the driver and filter lists. Selections made in a driver list determine what users can select in a filter list.
Many-to-many filtered picklists map multiple list items in a driver list with multiple list items in a filter list. For example, Executive, Senior Director, and Senior Manager in the Role list qualify for Plan A in the Compensation Plan list. The Senior Director and Senior Manager roles also qualify for Plan B.