During the creation and development of this book, the USB has progressed, since its introduction in 1996, through three iterations, and was scheduled for a fourth revision in 2019. In essence, the USB connection is a concept expressed as a written standard that describes an electro-mechanical and software protocol system through which a host computer is automatically interfaced to peripheral devices when a standardized electrical cable is plugged into each unit.
In USB 2.0 cables there are ...