According to WIKI:”Universal Serial Bus (USB) is an industry standard developed in the mid-1990s that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices”.
USB is a standard for the connection of computer peripherals such as keyboards, pointing devices, digital cameras, printers, portable media players, disk drives and network adapters to personal computers,it has the ability of communicate and supply electric power as well.USB has become commonplace use for other devices,including smartphones,PDAs and video game consoles.The most remarkable affect on USB is its replaced a range of previous interfaces, such as serial,parallel ports,as well as separate power chargers for portable devices.
And if you are looking deeper enough, you might realize that there are meanly four basic types or sizes of USB connectors.
- the earlier “standard” size, in its USB 1.1/2.0 and USB 3.0 variants (for example, on USB flash drives),
- the “mini” size (primarily for the B connector end, such as on many cameras),
- the “micro” size, in its USB 1.1/2.0 and USB 3.0 variants (for example, on most modern cellphones),the versatile “USB On-The-Go” scheme, in both mini and micro sizes.
Difference from data cables like Ethernet,or HDMI.each USB cable end with a different types of connector;such as an A-type or a B-type.Both of them are design for protect electrical overloads and damaged equipment,but only the A-type socket can offers power source.Since there are many cables along with A-type connectors on two ends,you must used it cautiously.Therefore,each different type of “sizes” requires four different connectors;USB cables are use for A-type and B-type connectors,while the corresponding sockets are available for the computer or electronic device.During the general practice,the A-type connector is always come to the full size,while the B-type side can be changed as required.
On the other hand,the “micro” size is the most durable designed for the insertion lifetime,because of the latching mechanism (parts providing gripping force)which moved into plugs on the cable side.USB connections also consists of four data transfer speeds: Low Speed, Full Speed, High Speed and SuperSpeed.High Speed is only supported by some specifically designed,USB 2.0 High Speed interfaces as well as by USB 3.0 interfaces.SuperSpeed is supported only by USB 3.0 interfaces.