Peripheral Devices

We explain what peripheral devices are in computing and the characteristics of each type according to their function in the system.

What are peripheral devices?

In computing, peripheral devices (also called just “peripherals”) are all those devices that connect to the CPU (Central Processing Unit o Central Processing Unit) to add functions or operations to the system but that are not a permanent part of it.

Computer systems traditionally comprise three basic operating units, of which the input and output subsystem, the same one that manages the peripherals, is just one. The others are the central memory and the CPU. The peripherals are part of the hardware.

The peripherals are classified according to their performance within the system, as follows:

• Input peripherals (input) which enter data into the system.
• Output peripherals (output) which extract data from the system.
• Input and output peripherals (i/o) when they fulfill both functions.
• Storage peripherals when they serve as an auxiliary to the system memory.
• Communications peripherals when they allow the system to communicate with someone else or some computer network.

See also: Components of a computer

Input devices

It is about those devices that serve only to enter data into the system that is, to capture new information or communicate the user with the system. Seen this way, they communicate the system with the outside world in different ways.

Examples of this type of devices are:

• The keyboard Thanks to which we can type commands into the system or create documents that will reside within it.
• The mouse or mouse. Introduced after the invention of graphical work environments, it allows us to introduce movements to the system, which interprets them within an axis of possible actions such as commands and actions (clicks).
• The scanners. Designed to graphically reproduce documents, similar to a photocopier, they enter data into the system by graphically digitizing text, QR codes, etc.
• The video cameras Attachments that perceive the real world and record it in a video, allowing its entry into the system.
• The microphones Similar to the previous case, but they record the sound of the real world. They can be incorporated into the same device.

Continue on: Input devices

Output devices

These are those peripherals that allow you to extract information from the system that is, receiving data from the system in the real world, through our senses. This is the only way in which the computer system can issue information and communicate with the user.

Examples of this type of devices are:

• The monitors On these screens the system can graphically represent the operations that occur inside it, and simulate various environments depending on the type of software in use. There we can read, watch videos or see other users who are connected to us.
• The speakers (speakers) Audio outputs only, which allow the system to emit various ranges of sounds, whether their own or third parties: play music, alert the user about something, etc.
• The printers These devices give physical presence to the system's information, either by writing it on paper using various mechanisms (ink, laser, etc.), or even sculpting it into matter (as is the case with 3D printers).

Input and output devices

Input and output devices are those that fulfill both input and output functions either simultaneously or at the user's discretion. These are bidirectional communication devices with the system.

Examples of this type of devices are:

• Multifunctional printers Capable not only of printing, but also of photocopying, scanning and reproducing, these devices serve as input or output as the user needs.
• Touch screens This is a specific type of monitor that replaces the keyboard with a screen sensitive to human touch, allowing the user to extract and enter information simultaneously.
• VR headsets Devices that occupy the user's entire head and that supplant the real world with a simulation offered in glasses in front of their eyes and speakers next to their ears, at the same time that they perceive the position of their head and feed the system with that information, in a simultaneous feedback exercise.

Storage devices

It is about devices equipped with their own memory (or rather a storage space) of a certain capacity, into which the data contained in the system memory can be copied, to be preserved, geographically moved or simply backed up.

Examples of this type of external devices are:

• The floppy disks Completely obsolete today, these small devices equipped with magnetic tape had a minuscule capacity compared to current computing needs, but they were the backup and data recovery mechanism available in the 1980s and early 1990s.
• Compact discs The well-known CDs, so popular in the music industry, were nothing more than an information storage device of any type, which worked based on a polished surface in which a laser produced computer-coded micro-tears.
• The pendrives The most recent version of the previous devices is the memory bar in which we store and transport information today, and which works based on microvariations of the electric current coming from the specialized port (USB) where they are connected.
• External drives Similar to pendrives but larger in size and greater storage capacity. They can store several terabytes of information.

Communications devices

Communications or network devices are those that allow the computer connection of the system both with other devices (cell phones, tablets, televisions, etc.), and with local computer networks or the Internet.

Examples of this type of device are:

• Network cards Chip platforms designed to manage an antenna sensitive to electromagnetic waves that carry network information, or an input port of a coaxial cable that fulfills the same role. However, usually these cards are not external devices, but rather one of their internal parts.
• Modems and routers Autonomous devices or devices physically located within the system, which allow the encoding and decoding of information packets that are transmitted through a computer network.
• Wireless devices Antennas and devices that allow the system to perceive electromagnetic radio waves, which allows communication without the need for cables (Wireless or WiFi).

Continue with: Hardware and software

References

• “Peripheral (computing)” on Wikipedia.
• “Peripheral devices that interact with the computer” (video) on UNAM Supercomputo channel.
• “E/S and I/O peripheral devices” (video) in Engineering Steps.
• “Peripherial Device (Computer Technology)” in The Encyclopaedia Britannica.