Say you just bought a new computer, and with excitement you unpack it and set it all up. The first thing you want to do is print out some photographs of the last family party, so it's time to head back to the store to buy a printer. A printer is known as a peripheral device.
A computer peripheral is a device that is connected to a computer, but is not part of the core computer architecture. The core elements of a computer are the central processing unit, power supply, motherboard, and the computer case that contains those three components. Technically speaking, everything else is considered a peripheral device.
However, this is a somewhat narrow view, since various other elements are required for a computer to actually function, such as a hard drive and random access memory, or RAM. Most people use the term peripheral more loosely to refer to a device external to the computer case. You connect the device to the computer to expand the functionality of the system.
For example, consider a printer. Once the printer is connected to a computer, you can print out documents. Another way to look at peripheral devices is that they are dependent on the computer system.
For example, most printers can't do much on their own, and they only become functional when connected to the computer system. There are many different peripheral devices, but they fall into three general categories. input devices, such as a mouse and a keyboard, output devices, such as a monitor and a printer, and storage devices, such as a hard drive or flash drive. Some devices fall into more than one category. Consider a CD-ROM drive.
You can use it to read data or music, input, and you can use it to write data to a CD, output. Peripheral devices can be external or internal. For example, A printer is an external device that you connect using a cable, while an optical disk drive is typically located inside the computer case.
Internal peripheral devices are also referred to as integrated peripherals. When most people refer to peripherals, they typically mean external ones. The concept of what exactly is peripheral is therefore somewhat fluid.
For a desktop computer, a keyboard and a monitor are considered peripherals. You can easily connect and disconnect them and replace them if needed. For a laptop computer, these components are built into the computer system and can't be easily removed. The term peripheral also does not mean it is not essential for the function of the computer.
Some devices, such as a printer, can be disconnected and the computer will keep on working just fine. However, remove the monitor of a desktop computer and it becomes pretty much useless. Here you can see a typical desktop computer system with a number of common peripheral devices. The central processing unit, motherboard, and power supply are the core computer system. Expansion slots on the motherboard make it possible to connect internal peripherals, such as a video card or sound card.
Other internal peripherals shown are a hard disk drive, and an optical disk drive, number 6. External input peripherals are a scanner, number 1, display monitor, number 10, keyboard, number 13, and mouse, number 14. External output peripherals are a set of speakers, number 9, and a printer, number 16. Note that labels 11 and 12 in the figure refer to software and are not peripherals. There are many other examples of peripherals, such as a microphone, web camera, headphones, external hard drive, and flash drive. Most computer users have at least several of these peripheral devices.
Internal peripherals are directly connected to the motherboard using one of the different types of slots on the motherboard. External devices can be connected using a wired connection or a wireless connection. As the name suggests, a wired connection uses a cable that needs to be plugged into the computer using a connector. The most widely used connector is a universal serial bus, or USB connection.
But several other types are used, depending on the specific computer system and the type of peripheral. A wireless connection does not require a cable. The most widely used wireless connections are Bluetooth and Wi-Fi.
Bluetooth is good for very short distances, so peripherals such as wireless mouse and keyboard typically use a Bluetooth connection. Wi-Fi is good for longer distances. If you have set up a wireless network in your home or office, you may be able to print wirelessly to a printer if it is also connected to the network. Computer peripherals expand the functionality of your computer. Some are essential for the computer to properly function, such as a monitor and a keyboard.
Others serve a more specialized purpose, but allow you to do a lot more with your computer.