A Dimmer or rheostat works by limiting or increasing the amount of electricity going to the heat source. You have to adjust it manually and keep an eye on the heat source temperature, adjusting it up to several times a day.

A thermostat has a temperature sensing probe that will adjust the amount of electricity automatically to a user set temperature. You set the temp once and leave it alone, just be sure the temperature in the enclosure is correct (it will not always be what the thermostat says).

Hope this helps... Does this mean I win?

Mike

What she said:

Quote Originally Posted by Michelle.C View Post
Rheostat/Dimmer = Controls temperatures by reducing the flow of electricity.

Thermostat = Controls temperatures by switching off the flow of electricity based on the temperature.