Plain English Meaning
The process by which one controller passes you off to another controller while you remain on radar. The first controller tells the next one who you are and where you are, the next controller agrees to take you, and then you are told to switch frequencies and check in with them.
Full Definition
The coordinated transfer of radar identification and control responsibility for an aircraft from one air traffic controller to another. Once the receiving controller accepts the handoff and the pilot is instructed to contact the new facility or sector on a new frequency, that controller assumes and responsibility for the .