A way to get a
internal combustion engine, usually a
2-stroke, started, as commonly used in
radio-controlled vehicles,
lawnmowers and the like.
Basically it works by you pulling a rope. The rope attaches to the piston, and by pulling the rope, you make the piston go up and down. As the piston pushes up, it compresses a mixture of fuel and air at the top of the cylinder, which hopefully then ignites. This pushes the piston back down, which forces it to bring in more fuel and air, which ignites and so on.
Other ways of starting an engine, include a kickstart (as used on most motorcycles) and starter motors.