What is a USB hub?
It seems nearly every electronic gadget manufactured today makes use of the ever-handy USB port. Early computers featuring USB normally had only one or two ports located inconveniently at the back of the case. Newer computers feature several built-in USB ports, and many cases now place two or more of these ports in front. Even so, additional ports are often needed, and having them conveniently accessible makes all the difference. The USB hub does just that. A USB hub is a small, light unit with multiple ports for plugging in USB devices. It is commonly connected to a USB port located on the back of a desktop computer by using an extension cable. Once the hub is plugged in, you can set it wherever is convenient, avoiding the hassle of accessing the rear of the system. A USB hub is also great for laptops with only one or two ports. Most hubs can support up to 127 devices. A self-powered USB hub can be used to connect digital cameras, card readers, keyboards, mice, MP3 players, memory sti
A hub is a USB device that includes extra ports into which other USB device can be attached. Some hubs, like the keyboard, are bus powered, deriving their power from a source on the bus to which they are attached. Others are self-powered. These come with an AC adapter that plugs into an electrical outlet and supplies power to the hub. There are several companies that sell hubs today. Some self-powered hubs are likely to function solely as hubs, acting as a source of power and allowing you to plug several downstream devices into them. Other devices may include a built-in hub (like the Apple USB Keyboard) that serve a primary function but also provide other ports into which another device can be connected.
A USB hub is a small box, outfitted with a number of Type A sockets, that lets you connect multiple peripherals to a single port on your PC. The hub generally has its own power source (typically an AC adapter) for the purpose of providing an electrical current to all of its sockets. You should consider using a hub if you have a lot of USB devices. You also should get a hub if you need to tether your PC to a USB peripheral, such as a printer or scanner, more than 5 meters away. As you may recall, the USB specification limits the length of USB cables to 5 meters in length. However, the specification also lets you daisy chain as many as five hubs, for a total length of 25 meters (or 30 meters if you include a 5-meter cable on the ultimate device). Hubs are not expensive. The average hub sells for $50 to $80 and has four ports, although you can find hubs available with more ports. Adaptec (http://www.adaptec.com), Belkin (http://www.belkin.com), IOGEAR (http://www.iogear.com), and Orange M
