Record of the year deals with a specific recording of a song and recognize the artists, procedure and engineers who contribute to that recording.while song of the year deals with the composition of a song and recognize the songwriters who wrote the song.
The record of the year distinguishes a single track from and album ans goes to multiple people involved in one project: artists, producers and engineers who conceived a particular recording.
MF means mezzo forte in music. It is one of the dynamics to tell you to play loud or soft. So in this situation, mezzo forte or MF is telling you to play moderately loud.