USB - Stands for Universal Serial Bus.
USB is one of the main ways that peripherals connect to computers. iPods connect to computers and sync data between the two using USB.
USB connections are generally achieved on computers by plugging USB cables into USB ports on computers and peripherals. USB is denoted with the icon shown on the Wikipedia page linked to below. Multiple USB devices can be connected to each through "hubs" - multiport devices that allow all items connected to them to work with a computer.
Maximum Connection Speed
USB 2, the most common current kind of USB connection, can transfer data at up to 480 Mbits/second.