Universal Serial Bus
The Universal Serial Bus (USB) combines all of the advantages of a multiplatform standard including decreased cost, increased compatibility, and a greater number of available peripherals.
USB peripherals deliver on the promise of plug and play convenience by eliminating the need to turn off or restart the computer when attaching a new peripheral. Users can connect USB peripherals whenever they need them. For example, a user engaged in producing a newsletter or illustrated report could easily swap out a digital camera for a printer without any downtime.
When a USB peripheral is first attached, the user installs a device driver by dragging its icon onto the System Folder or by running a simple installer application. This only needs to be done once and the device is then available, since USB supports dynamically loading drivers.
USB connections require no terminators, memory addresses or ID numbers. They also use a new kind of cable - small, simple, inexpensive, and easy to attach. There's only one style of cable (USB A-B), with different connectors at each end, so they can't be plugged in incorrectly.
USB supports simultaneous connection of up to 127 devices by attaching peripherals through interconnected external hubs. When a computer's ports fill up, users simply attach a device called a hub, which provides additional ports (usually four or seven), and can keep on plugging in more peripherals - and hubs - as needed.