The name 2-stroke itself explains that 2- stroke engines use engine cycle which lets the car run in 2 steps, in layman language. 2-stroke engines are usually light and hence cannot generate much power when compared to 4-stroke engines. So they are mostly used when low RPMs are required.
The name Otto is not picked from any physics book nor it is any phenomenon. Otto was the last name of Engineer Nikolaus Otto who created the very first working four-stroke engine. Four-stroke engines with spark plugs are also called as Otto engines. Otto cycle is basically the thermodynamic cycle on which a four-stroke engine