What Is USB USB Short for Universal Serial Bus, an external bus standard that supports data transfer rates of 12 Mbps. Today just about every PC comes with Universal Serial Bus, or USB ports. In fact, many computers will even have additional USB ports located on the front of the tower, in additional to two standard USB ports at the back. In the late 1990s, a few computer manufacturers started including USB support in their new systems, but today USB has become a standard ...