Your computer has Universal Serial Bus (USB) ports that let you easily connect external devices, such as a keyboard, mouse, joystick, printer, scanner, iPod, or digital camera, without needing to restart your computer. The USB ports provide some power, so most devices don’t need their own power cords. You may be able to purchase adapters that let you connect non-USB devices to a USB port.

If you have a portable computer, USB devices can cause your computer battery to become depleted faster. If you are using the device for an extended period, it is a good idea to connect the computer’s power adapter.

You can connect more than one device to a USB port by chaining the devices together or using a USB hub. To chain devices together, connect one device to another with a USB cable and connect the last device to the computer. To use a USB hub, connect the devices to the USB ports on the hub and then connect the hub to the computer. Most USB hubs have a power adapter and should be plugged into an outlet.

High-speed hubs can support USB 2.0 high-speed devices as well as USB 1.1 compatible devices. USB 1.1 hubs don’t allow high-speed USB devices to operate at their maximum data speed. Some USB devices may not work when connected to a hub that operates at a slower speed than the device. If a device isn’t working, make sure it’s not connected to a hub that operates at a different speed.

For more information about USB devices, hubs, and adapters available for your Mac, see the Macintosh Products Guide website.