The operating system supports USB as well, so the installation of the device drivers is quick and easy too. In this edition of How Stuff Works , we will look at USB ports from both a user and a technical standpoint. Printers connected to parallel printer ports, and most computers only came with one. Things like zip drives in need of a high-speed connection into the computer would use the parallel port as well, often with limited success and not much speed. Modems used the serial port, but so did some printers and a variety of odd things like palm pilots and digital cameras.
Most computers have at most two serial ports, and they are very slow in most cases.
Devices that needed faster connections came with their own cards, which had to fit in a card slot inside the computer's case. Unfortunately, the number of card slots is limited and you needed a PhD to install the software for some of the cards. The goal of USB is to end all of these headaches. Each device can consume up to a maximum of 6 megabits per second of bandwidth, which is fast enough for the vast majority of peripheral devices that most people want to connect to their machines. Just about every peripheral made now comes in a USB version.