Freestanding:  Towel warmers that are moveable and are not stationed to the wall. Hardwired:  Wired directly into your electric.  Most mounted towel warmers will either be hydronic or hardwired. Hydronic:  Heated by circulating warm water. Mounted:  A towel warmer that is permanently mounted to a wall. Plug in:  Plugs directly into a outlet.    All Freestanding towel warmers will be plugged in.