Glossary of Unfamiliar Terms
Step Stage - This is the simplest heating and cooling control method.  As the zone's air temperature deviates more from the setpoint, progressively higher stages of heating or cooling are used.  The problem with this approach is that this program can easily become 'satisfied' when the zone's air temperature is still several degrees away from the setpoint.

If you only have 1 or 2 stages of heating AND cooling in a zone, this program usually works as well as any.