Each USB connector interface of the computer: It can supply voltage DC5V and current up to 500MA. However, there are a lot of new motherboards with USB ports that can already supply 1.5A of current, refer to the motherboard manual. Generally, the USB interface of the motherboard provides current of 500MA. The voltages are all labeled 5V.
USB, which is the abbreviation of English Universal Serial Bus, and its Chinese abbreviation is "Through String", is an external bus standard used to regulate the connection and communication between computers and external devices.