The AT90USB162 is a microcontroller (MCU) from Atmel (now part of Microchip Technology) that features USB functionality. It can be used in various USB devices such as USB keyboards, mice, game controllers, and more. The AT90USB162 provides built-in USB support, so it's capable of acting as both a USB host and device.
In the context of the Windows driver, you're likely referring to the USB driver that allows Windows to recognize and communicate with the AT90USB162 when it is connected to a computer via USB. This is essential if you're programming or interacting with a device that uses this microcontroller, or if you're trying to use the device as a USB peripheral (like a keyboard, mouse, or custom device).