A Universal Serial Bus (USB) switch allows two or more computers to easily share USB peripherals like printers, cameras and scanners. The USB switch eliminates the need to unplug the USB peripheral component from one computer, to plug it into the other. Instead, the shared component runs to the USB switch device itself, which is connected in turn to multiple computers. With the touch of a button on the USB switch device, the peripheral is instantly available to serve any computer connected to it.

There are several models of USB switches. Some models are built for two computers to share a single device. This can be handy for a home user who needs to share a USB-enabled printer, scanner, memory card reader or digital camera, for example, between a desktop and laptop. Other models allow incoming ports or connectors for up to four computers, and an outgoing USB port for one device. Still others allow up to four computers to share up to four USB-enabled devices.

On most models a small LED light appears over each incoming port, lighting when the particular port is active. With a press of a button, the USB switch rotates the active port.

Without a USB switch, computers must be networked to share devices. Though networks are great for many purposes, not everyone needs a network. Moreover, even with a network a USB switch can come in handy.

For example, let’s assume you have a home desktop computer networked to a laptop. Connected to your desktop is a memory card reader. Let’s assume further that you want to use your card reader to download images to your laptop. Unless you leave your desktop powered up and running, you’ll be forced to either boot up the desktop to gain access to the network and card reader, or you’ll need to unplug the card reader and plug it into the laptop.

Using a USB switch, you would not need to power-up the network, nor move the device’s plug or interface. With the needed card reader connected to a USB switch, you would simply connect your laptop to the incoming port on the USB switch and use the memory card reader, hassle-free.

In some cases a user might need the opposite of what a USB switch provides. One might require several USB ports for a single computer. A USB hub serves this purpose. It is a device that plugs into a USB port, allowing several incoming USB connections.

Note that built-in USB ports on a computer are powered, but simple hubs are not. Some devices, like digital cameras and rechargeable MP3 players, require a powered USB port to function. If you require powered USB ports, look for a powered USB hub, which comes with its own power adapter that plugs into the wall. These hubs are slightly more expensive than non-powered hubs.