An increasingly popular choice this days is infrared heating systems. Before entrusting the comfort and safety of your family to such as system, it is a smart idea to know how they work.
Infrared is the main way that the heat of the sun reaches us hear on earth. There is no heat source to compare to the sun, so it is clear that infrared can really provide some heat.
What happens between the sun and the earth is that radiation energy from the sun is transferred to the earth via infrared waves. The process is called heat transfer.
Infrared is not the most common way that home heating systems work however. Something like propane space heaters will use mainly convection. This is the second type of heat transfer and works by moving air around - warmer air shifting colder - and it works in any gas (like air) or liquid (a kettle).
There is only one more type of heat transfer - conduction. This is when two bodies are touching and heat flows from one to the other. It is also seen in home heating - for example in a radiant heat floor system. The heat transfer by conduction is from the floor to the human being standing on it.
The thing that is special about infrared heat is that it can travel through a vacuum, which is why it is the way the heat of the sun reaches us.