A type of game controller that is designed to be a portable version of an arcade cabinet's ball joystick and large buttons. It is designed to be a home version of a cabinet's setup, making arcade ports for consoles easier to play.
The Japanese term for it is "arcade controller" (アーケードコントローラー). In English it's also known as a "fightstick", since it's especially popular with fighting game enthusiasts.
This tag implicates game_controller and joystick (learn more).