Here are the important characteristics of game controllers:
The first game controllers were joystick controllers, which are still popular and still most appropriate for playing flight simulator and air combat games. Some are marginally usable for some driving, racing, action/adventure, and sports games. Steering wheel controllers, many of which include foot pedals, are ideal for driving/racing games and some flight simulators, but ill-suited to other games. Gamepad controllers are suitable for action games, including first-person shooters, sports, and most arcade-style games.
An axis is a line drawn through the center of the joystick (or the D-pad on a gamepad) that defines the directions that one can move by manipulating the controls. All controllers have an x-axis (side-to-side movement) and a y-axis (front to back). Some controllers add a z-axis (up and down) and/or a throttle axis. Depending on the controller type, the third and/or fourth axes may also be called a yoke control or rudder control, for their intended function, or a twist control, for the method used to activate the axis.
The throttle is a variable input, present on most joysticks and some gamepads, and normally assigned to the third or fourth axis on the controller. The throttle is usually used to control vehicle speed, and may be a slider, wheel, pedal, or variable-pull trigger, depending on the controller.
Motion along an axis can be tracked ...