What does USB stand for?
USB stands for Universal Serial Bus.
USB is a replacement for many of the older legacy technologies
such as serial and parallel interfaces. USB makes your life easier
by not requiring drivers (for the device itself), being widely
available and having the ability to draw power. By drawing power
directly from your computer you can avoid having to provide an external
power source to many USB devices (though some power-hungry devices
do still require an external power source because they can't draw
enough from the USB port).
Universal Serial Bus is also Plug-n-Play - you can plug your
USB devices and they will generall be recognized (and in many
cases just start working) without you needing to do anything. If a
driver is needed you should have an option to automatically scan the
internet for available drivers - this stuff couldn't be any easier.
USB 1.1 and 2.0 are widely available (though by now most
products have been upgraded to 2.0), but now a new interface known as
USB 3.0 is slowly is making it's way to the market. It will
probably be a few years before 3.0 devices are widely available and we
anticipate that active extension cables will be widely available when
the interface is more common.