Heat is something with high temperature and high movement, if you take it away it turns cold and not a lot of movement happpens.
A conductor is something like a wire or a pan, something that conducts (lets heat flow through easily) heat.
An insulator is something that keeps the heat in, like a jacket, so when you touch a wire it doesn't shock you because there is an insulator around the wires.
Buoyancy is the upward force of water on an object to keep it floating.
Magnetism is the force of to magnets, or something magnetic, when they come together to form magnetism.