Control is the ability to throw accurately.
Command is the ability to throw accurately with good stuff.
In other words the ability to throw strikes without getting hit hard.
A pitcher can have good control without having good results.
A pitcher with good command will most always dominate because he also has good life and movement on his pitches.
A pitcher with an 80 mph “straight” fastball and a “early breaking round house” curve ball can throw strikes and locate the ball all day. He has great control and sometimes that can work, but despite succress he will never be described as having great command!
The higher the level the more the above holds true. There are a few exceptions!