Controller support refers to a feature or functionality that allows users to interact with and control external devices, such as game controllers, keyboards, mice, or other input devices. This means that a device can be connected to another device (such as a computer or gaming console) and used to control it through various inputs like buttons, joysticks, and triggers. The term "controller support" typically refers to the ability of a system or software application to recognize and interpret these inputs from an external controller, allowing users to interact with their devices in a more intuitive way.