A:Answer Hello! They are actually the same cable. USB-A indicates the shape of the USB plug, as there are at least 5 different types of USB shapes, and USB 3.0 indicates how fast the USB will transfer data. The C920s uses the rectangular shaped USB, which is USB-A, but uses USB 3.0 technology to transfer the data from the webcam to your computer, in the same cord. They will both work with your computer as long as your computer has the rectangular USB ports. I hope this wasn't too confusing!