What Is USB and How Does It Work?
USB stands for Universal Serial Bus which is a type of interface or connection on your home computer (PC or Mac). USB was originally designed to allow multiple external devices to be connected to a computer and offer high speed data transfer between all those devices. It has now become hugely popular as an interface on a huge variety of devices from laptops to digital cameras and MP3 players.
You can easily identify a USB device from the following symbol:
USB is designed along a daisy-chain principle where up to 127 devices can be connected to one single chain. The chain itself must consist of devices and hubs. The hubs were designed to allow one USB connection from your computer to then split off to 5 separate devices. This was when computers only came with one 2 USB ports. Most modern computers have 6 - 8 USB ports and LCD screens also normally features one or 2 "spare" USB ports. This has almost removed the need for USB hubs altogether.
USB devices operate at 3 different speeds/data transfer rates. They are:
Low - 1.5Mbits/s
Full - 12Mbits/s
High/USB 2.0 - 480Mbits/s
Bear in mind that all of the above are theoretical transfer rates and in a real world situation this data bandwidth would be split between several devices and would be lower because of tha - and this is quite often the case.