Control Plate: The metal plate onto which the switches and potentiometers are mounted (mainly on Telecaster guitars and Jazz Bass).
Jack Plate: The metal or plastic base that holds the cable jack socket (e.g., Les Paul square metal plate, Strat recessed cup, Tele Electrosocket/Cup, Cat's Eye/Football plate).
Neck Plate: The rectangular metal 4-bolt plate that connects the neck to the body of the guitar.
Tremolo Plate: The plastic rear cover that hides the tremolo springs (mainly on Stratocasters).