Your PC comes with a limited number of serial and parallel ports for connecting input and output devices. However, you may find it necessary to attach an extra input or output device to the PC. The motherboard has a set of sockets called expansion slots, that help you attach extra input and output devices, in case you run out of ports. These slots can be used to add extra memory and additional devices.
Attaching a device to a PC is an easy task. You need to buy an appropriate add-on card or an option board. This card contains the electronic components, which interface the input and output device with the motherboard. In addition, it provides a port to which you can connect your device. Next, you open the system unit, plug the card into an empty expansion slot and attach the device to the card's port. Now the device is connected to the motherboard.
