The three main control surfaces required for a controlled flight are the Elevator, Rudder and Ailerons.
Ailerons are located on the wings and are used to bank or roll the aircraft.
They basically increase and/or decrease the lift on either of the wing surfaces. When one side aileron deflects downwards the other deflects upwards thus increasing lift on one side and reducing lift on the other side of the wing to create rolling moment about the longitudinal axis.
Elevator is seen usually at the rear end of the aircraft within the horizontal stabilizer.
Elevator is used to pitch the aircraft up and down. Elevator deflect up or down increasing or decreasing lift on the horizontal stabilizer creating a pitching moment about lateral axis.
Rudder is mounted on the vertical stabilizer of the aircraft.
It deflects left or right increasing or decreasing the lift on the vertical stabilizer thus generating a moment about the normal axis.
It help`s to yaw the aircraft.