External hard drive USB connection

[trixilator]

I've just been given a usb connected external hard drive for my sony laptop. The usb connection cable has a second usb connection leading from it which has me completely confused! He is unavailable to ask for help - can anyone explain briefly how this works? Appreciate any help. Many thanks

[Old_Geezer]

The only external drives I have, have a data cable (USB) to plug into the PC, and a power cable to power it. Not sure about 2 USBs. Maybe it is so you can chain multiple drives to the same USB input ?

[ChuckFickens]

The two USB connectors are so you can use it on USB1 ports as they are unable to supply enough power from a single port. if you are using the drive on USB2 connectors (all modern stuff will have USB2) you only need to use one connector, normally the one with the two cables coming out of it.

[trixilator]

Thanks for prompt replies - now I know what I'm doing.