Ailerons control the Roll axis, keeping the wings level, or rolling one wing up, and one down. Ailerons are usually on the back side of the main wing, closer to the tip.
Elevators move the nose up or down, changing the Pitch axis, also known as Attitude. Elevators are usually part of the tail.
Rudder moves the nose right and left, changing the Yaw axis. The rudder is usually part of the tail.
Flaps change the shape of the wing to add lift and reduce speed. Flaps are often used during landing, and sometimes during take-off. Flaps are usually on the back edge of the main wing, closer to the center of the plane.
Spoilers reduce lift by spoiling the shape of the wing, like air brakes. Spoilers can be used while landing to give better traction for the tires on the runway. Spoilers can also be used during flight to descend quickly, if necessary. Spoilers are usually on the top of the wing.