HID

HID, or Human Interface Device, is a class of computer peripherals that interact directly with humans and are supported by standard device drivers on major operating systems. The term most commonly refers to devices that capture human input—such as keyboards, mice, game controllers, and touch or stylus input—and to the USB class specification that defines how these devices communicate with hosts. Bluetooth and other transports include HID-compatible profiles as well.

Technically, HID devices describe their data format using a HID report descriptor, which declares the structure of the data packets (reports) exchanged between device and host. Reports can be input, output, or feature. The host typically polls or receives asynchronous reports via interrupt endpoints. A key feature of HID is abstraction: the host software does not need to know the device internals; it works with logical usages defined in the HID usage tables.

History and standardization: The HID specification is published by the USB Implementers Forum and defines the protocol, report formats, and usage pages used by many input devices. It applies to USB as well as HID over Bluetooth, enabling cross-platform compatibility for a wide range of devices.

Software support: Operating systems include built-in HID drivers that handle device enumeration, input processing, and event generation. In Linux, the hid subsystem and hidraw interface allow raw access to HID data; in Windows, the HID class driver handles most devices with user-space APIs available through various frameworks; in macOS, IOHIDFamily provides support.

Security and privacy: Because HID devices can inject inputs, they are subject to security considerations such as spoofing and unauthorized access. Systems often provide controls to manage device permissions and trusted peripherals.