The HID device class code is "0x03, this class is used for devices operated by human, devices like keyboard, mouse, joystick and so forth.
The advantage of HID devices is that, they don't require to install drivers, in most modern operating systems, the device will be detected without any problem.
The USB HID protocol allows a personal computer to recognize a USB HID connected to it without the need to create a device driver, this is the same like when you connect a USB optical mouse or a USB keyboard you don't need to install drivers for that. Windows operating system will load the required drivers, all that is needed is to to supply the PC with a descriptor file containing some information from the device like Vendor ID (VID), Product ID (PID), Manufacture name and so forth.
MikroC Pro for PIC provides USB HID library that make it easy for a host device to communicate with a slave device on a USB bus.