USB, short for Universal Serial Bus, is a standard plug-and-play connection type for many types of devices. Generally, USB refers to the types of cables and connectors used to connect these many types of external devices to computers.

The Universal Serial Bus standard has proven to be extremely successful. USB ports and cables are used to connect hardware such as printers, scanners, keyboards, mice, flash drives, external hard drives, joysticks, cameras, monitors, and more to computers of all kinds, including desktops, tablets, laptops, netbooks, etc.

USB has become so common that you'll find the connection on almost every computer-like device, including game consoles, home audio-visual equipment, and even in many cars.

Before USB, many of these devices were connected to a computer via serial and parallel ports, such as PS/2.