USB Refers to

A Port Type

Universal Serial Bus short for USB is an industry standard developed that defines the cables, connectors and communications protocols used in a bus for connection, communication and power supply between computers and electronic devices. It was designed to standardize the connection of computer peripherals  like as keyboards, pointing devices, digital cameras, printers, portable media players, disk drive and network adapter, to personal computers, both to communicate and to supply electric power. It has become commonplace on other devices, such as smartphones,  PDAs, and video game consoles. USB has effectively replaced a variety of earlier interfaces, such as serial and parallel ports.