Under Floor heating is provided by installing pipes within the floor, the pipes are then heated by the boiler which in turn heats the entire floor area. This does away with the need for radiators giving the room a clean look.
Additional benefits are that it makes traditionally cold tiled surfaces comfortable to walk on, even in the middle of winter.
How does underfloor heating compare to radiators?
Under Floor heating is slower to warm up than radiators, but retains heat better. So if your house is occupied most of the day it can be more beneficial. If however, you are out for long periods of time, the faster heat up time of radiators would probably suit you better.
It is possible to split your home into zones by having under floor heating in some rooms, and radiators in others. The ideal split would be radiators upstairs with under floor heating downstairs.