It could be electric which is:
- cheap & easy to install,
- can be easily installed in one room,
- can easily be installed in existing house without major upheaval and without raising the floor level,
- can be cheap to run depending on various factors.
It could be an hydronic underfloor heating system, also called a wet heating system because is uses water filled pipes laid under the floor with the heating from:
- any type of central heating boiler (gas, electric or oil);
- or a heat pump.
Wet underfloor heating is expensive to install and the work involved means it is normally only done throughout new buildings. This sort of system can be bought as a kit to install in just part of a house, for example, in one room or in a new extention to an existing building.
The same one boiler can run both underfloor heating and traditional heating with radiators if it is correctly sized and installed. This is not generally a DIY job.
You will find more information about underfloor heating projects in the blogs added to this site over time.
In this little clip you can see an expert opinion on radiators versus underfloor heating.
Just one small point I should point out is that he says UFH takes hours to warm up, this is not always the case and some installations will reach temperature within 30 minutes.