In computing, the USB human interface device class (USB HID class) is a part of the USB specification for computer peripherals: it specifies a device class (a type of computer hardware) for human interface devices such as keyboards, mice, game controllers and alphanumeric display devices.
More information on Wikipedia.
usb_host_class_hid
Source code: src/drivers/usb/host/class/hid.h, src/drivers/usb/host/class/hid.c
drivers/usb/host/class/hid.h