noun
active area
Computing term referring to the region of a screen or interface where user actions are registered.
このボタンの動作領域は狭すぎて押しにくい。
The active area of this button is too small and hard to press.
タッチパネルの動作領域を設定する。
Configure the active area of the touch panel.
Compound of 動作 (operation, action) and 領域 (area, region). A straightforward technical term.