Definition: Changes to the tilt of the main rotors on a helicopter are cyclic controls. Changing the tilt or pitch of the main rotors and blades changes the direction of movement of the helicopter.
Cyclic forward / backward or cyclic pitch would be the same as forward or backward pitch or elevator control, moving the helicopter into a dive or climb. Cyclic left / right or cyclic roll would be the same as left or right banking or aileron control, turning the helicopter to the left or right.
On a typical full-size helicopter, the cyclic control stick is in front of the pilot's seat. The cyclic controls are controlled by the right stick of the RC helicopter transmitter.