The GamepadButton interface defines an individual button of a gamepad or other controller, allowing access to the current state of different types of buttons available on the control device.
GamepadButton
MDN Reference
The GamepadButton.pressed property of the the button is currently pressed (true) or unpressed (false).
GamepadButton.pressed
true
false
The touched property of the a button capable of detecting touch is currently touched (true) or not touched (false).
touched
The GamepadButton.value property of the current state of analog buttons on many modern gamepads, such as the triggers.
GamepadButton.value