Universal Serial Bus, the English abbreviation of universal serial bus, USB is a serial bus standard for connecting computer systems and external devices, which is used to standardize the connection and communication between computers and external devices. It was jointly formulated by computer companies and communication companies such as Intel, Compaq, Digital, IBM, Microsoft, NEC and Northern Telecom in 1995, and gradually formed the industry standard of communication between computers and peripherals.

USB interface form

USB is a necessary interface for computer external connection, which can be called universal interface. It can be divided into type A, type B and type C. Usually, it is type A.

1.Type A rectangle, generally used in personal computers, is mainly used to connect mobile phones, wireless network cards, USB flash drives, mobile optical drives, small-capacity mobile hard disks, etc., and is the most widely used.

2.Type B is generally used to connect 3.5-inch mobile hard disks, printers, and monitors.

3. The upgraded versions of Type C Type-A and B are oval, which have the characteristics of supporting positive and negative symmetric plugging and unplugging (both sides can be plugged in), supporting greater power transmission and bidirectional power transmission, and the interface is slim, and it integrates functions such as charging, display and data transmission.

The size is about 8.3mm×2.5mm, which gradually replaces the Micro USB interface. Type C appeared after USB 3.1, and its highlights are slimmer design, faster transmission speed (up to 10Gbps) and more powerful power transmission (up to 100W). Solved the worldwide problem of "USB can never be plugged in correctly".