USB (Universal Serial Bus) – definition


A desktop computer, a mobile phone, and other wired electrical devices may all connect via the USB protocol. A cable with connectors on either end makes the connection. All USB cables have a single end that fits into the computer, however USB cables can have different ends that plug into mobile devices, including miniUSB, microUSB, and proprietary connectors.

Maximum rates for USB version 1.1 are 1.5 MB/s, whereas the current version 2.0 is nearly 40 times quicker. The slower device limits the speed whereas the versions are backwards compatible. On a desktop computer, drivers may need to be loaded in order to transfer data, however some phones provide “mass storage” mode, which makes them appear to the computer as thumb drives without the need for additional drivers.

The electric charge that USB cables transport may be used to power peripherals (such USB mice or keyboards) and many mobile phones can be charged using a USB port in addition to their data transfer function.

Standard Also Known As Year Introduced
USB 1.1 Full Speed USB 1998
USB 2.0 Hi-Speed USB 2000
USB 3.2 Gen 1 USB 3.0 USB 3.1 Gen 1 SuperSpeed 2008 (USB 3.0) 2013 (USB 3.1)
USB 3.2 Gen 2 USB 3.1 USB 3.1 Gen 2 SuperSpeed+ SuperSpeed 10Gbps 2013 (USB 3.1)