A USB hub is a USB expansion device that is used to expand one USB interface into multiple USB interfaces, thereby enabling multiple USB devices to be connected to the computer at the same time. USB hubs can generally connect up to 4 or more USB devices at the same time. Different types of USB devices such as mice, keyboards, USB flash drives, external hard drives, printers, and more can be easily connected by plugging into the USB hub.
The USB hub can also provide power to USB devices, so it can charge USB devices, such as mobile phones, tablets, etc.
In short, a USB hub can connect multiple USB devices and provide power, and expand the USB interface of the computer, which is very convenient and practical.