Both are used for heating stoves. Propane has a lower boiling point than butane so it will continue to convert from a liquid to a gas even in very cold conditions, down to -45ºC. When the fuel needs to be stored for a long time, propane is a better choice than butane.
Propane gas cylinders contain considerably greater pressure than Butane cylinders and as a result, regulators are designed for use with either Propane or Butane and are not interchangeable because of their different design pressures and the different connections on the cylinder itself. I doubt you will be able to find and fill butane bottles easily.
We had an electric stove aboard for ten years, so every time we wanted to heat something other than in the microwave, we'd have to start the genset. Boy, is that a PITA, and electric burners are not nearly as controllable as gas. No proper chef would cook on an electric stove.