Basically, insulation is what keeps the hot air from wither leaving or entering the house, depending whether it’s winter or summer. But besides the insulation you will also need the constant heat supply source. So, the benefit of the insulation is that it saves you a lot of energy because the heat just stays in.
Conduction is the process involving heat transfer from a material to another through molecular at the moment they touch each other. Many substances handle conduction, but it differs from one to another whether they are good or bad conductors. The good conductors are gold, silver and copper down and the worst are wood and thermal insulating materials.
Convection is a process through which solids lose or gain heat when getting in contact with liquids. The change in temperature occurs in just some parts of the fluids causing an alternating density in the liquid. The forced convection is the opposite of the process described above, which is the natural convection.
Radiation is the process through which heat transform in energy, similar to radio and light waves. The difference is that this process doesn’t need air to happen.