Universal Serial Bus (English: Universal Serial Bus, abbreviation: USB) is a serial bus standard, is also a technical specification of input and output interface, is widely used in personal computers and mobile devices and other information and communication products, and extended to photographic equipment, digital television (set-top box), game consoles and other related fields. The latest generation is USB4, with a transmission speed of 40Gbit/s, a three-stage voltage of 5V/12V/20V and a maximum power supply of 100W. The new Type C interface allows forward and reverse blind plugging.

USB connector mainly has the following advantages:
1. Can be hot-swappable. That is, when users use external devices, they do not need to shut down and then turn on the computer, but directly plug in the USB for use when the computer is working.
2. Easy to carry. Most USB devices are known for being "small, light, and thin". For users, it is very convenient to carry a large amount of data with them. Of course, USB hard drive is the first choice.
3. Uniform standards. Common are IDE interface hard disk, serial mouse keyboard, and parallel printer scanner. However, with USB, these application peripherals can all be connected to personal computers with the same standard. At this time, there are USB hard disk, USB mouse, USB printer, etc.
4. Multiple devices can be connected. USB often has multiple interfaces on personal computers and can connect several devices at the same time. If a USB HUB with four ports is connected, it can be connected again. Four USB devices, and so on, can be connected to one personal computer at the same time without any problems (note: up to 127 devices can be connected).