(Using Electric motors as the thing that makes your plane fly)
Firstly the difference between old '2-stroke fuel engines' and 'Electric motors'. We’re moving progressively from internal combustion engines into the increasingly popular field of electric power.
When we talk about 'Electric motors' we're going beyond the idea of radio controlled '2-stroke fuel engines' and moving into the current idea of RC flying.
With electric motors we are no longer mixing fuel and changing glow plugs. We are no longer hoping the air-moisture won't 'cut the engine' or make it 'run lean, or rich'. We are no longer 'running in' the new engine. Best of all we aren't dragging around a heavy weight just to be in the air. Electric motors are cheap, reliable, versatile, and so much more fun.
So let's sum up before talking more about 'electric flight'
Old 2-stroke fuel engines: Are traditional, unreliable, hard work and noisey
Electric motors: Are easy, fast and fun.
I'm not going to go into a lot of detail about electric flight because you can YouTube the hell out of the finer points. However it goes without saying if you're entering this hobby, electric flight will save you time, money and help you get the most enjoyment out of the hobby today.
You can buy ready to fly electric planes that come with their transmitter, or will 'bind' with your own transmitter. These are call 'Ready to fly' or 'Bind and fly'. They usually come with all you need including the plane, battery, charger and the radio gear. They're a great way to start the hobby and get you in the air.
When you learn more you might want to start designing and building your own planes. For me this is where the real fun begins. You can buy the radio gear, motors and speed controllers (ESCs), servo's and batteries separately and start experimenting. This is where you free your mind and enjoy the idea of flight. there are a lot of websites and plans out there. so what's stopping you?