Components of a computer

You have probably ever wondered what is inside your computer . It is something that at some point makes us all curious.

To put it in simple and straightforward terms,  a computer is a computer system made up of various electronic components. All components work together to provide processed output data.

These components make up the so-called hardware ,  and are responsible for processing all the instructions provided by the software  with which the computer is loaded.

But in addition to that, you must bear in mind that a personal computer has external and internal components . Each one fulfills a specific function.

Being able to recognize the basic differences between software and hardware , such as the functions that each component has, will allow you, for example, to  build your own computer or repair it.

What will you find here: What is hardware and software? Types of computer components. What are the internal components? What are the external components? How to choose the components of the PC?

Internal components of a computer

Hardware and software

The first thing you should know is that  a computer is basically made up of two basic aspects: Hardware and software.

If you want to know more in depth about it, we recommend you visit this article: What is Hardware and Software? 

Computer hardware

Computer hardware can be defined as all those physical or material parts that can be seen and touched.

Examples of hardware are the  monitor, keyboard, mouse, hard drive, cabinet, and so on . That is, the device itself with its internal and external parts.

In short, the computer could be defined as a box to which a series of devices known as input and output devices are connected .

Interior of a computer cabinet

These devices or peripherals are used to enter and extract information . The box we are referring to is the brain of the computer and is where information is processed.

Learn more about computer peripherals in these articles: Input Peripherals and Output Peripherals .

Computer software

Broadly speaking, computer software could be defined as the set of instructions that computers use to manipulate and process data .

Keep in mind that without the software the computer would be  a collection of physical devices with no use . Something similar to having a body without a brain that tells you what to do with arms, legs, mouth, and other limbs and organs.

System software is a type of application that allows information processed by production or application software to be transformed into understandable instructions for hardware components.

That is to say, its function is to communicate the hardware elements with the different programs that you use to carry out specific tasks.

Computer software

This category includes, for example, device drivers and operating systems.

To learn more about device drivers, we recommend you read this article: What is a Driver or Controller?

Regarding operating systems, currently the most used are:

  • Windows
  • Linux
  • Android
  • MacOS
  • ios

Learn more about computer operating systems in this article: What is an operating system?

We also invite you to read this article in which you will learn about the operating systems used by phones: Mobile operating systems

Components of a computer

As you well know, there are different types of computers . Each of them includes essential and specific components for specific tasks.

Learn more about the different types of computers in this article: Differences between a notebook, laptop, netbook, hybrids, ultrabooks and PC

Components of a notebook

However, there are a number of basic components that they all share . In short, they are essential for the functioning of the PC.

If out of curiosity you want to know what elements make up your computer , or you are interested in building your own PC, join us in mentally disassembling a computer to learn more about all its internal and external components.

Also, if you want to know more about computers, we recommend you read this article: The first computer

In the event that you have decided to build your own desktop PC, keep in mind that for this it is not necessary to have a deep knowledge about the operation of the different components.

Of course, it will be essential that you know that all these elements must be compatible , and that you place them in the correct way within the cabinet.

To learn more about the elements that your PC includes, we invite you to read this article: What components does my PC have? How to use Speccy to find out

External components

External components are those that are not part of the main device of the computer.

Therefore it can be said that its function is complementary to the internal components .

The most common external components are:

  • Cabinet
  • Monitor or screen
  • Mouse
  • Keyboard
  • Speakers
  • Microphone
  • Webcam
  • Printer
  • Ports and connectors
  • Scanners
  • Video game controls
  • MIDI
  • Fingerprint sensor
  • Code bar scanner
  • Specialized teams (medical and musical, among others)


Also known as a system unit, it is the core of a computer system .

It is usually in the shape of a rectangular box, and inside are many electronic components that process information.

Computer cabinet

Basically inside the cabinet you will find the CPU or processing unit , which works as the “brain” of the computer, as well as the  RAM memories , the motherboard, the hard disk, among others.

One important thing to keep in mind is that virtually every component in a computer is wired to the system unit.

The cables are connected to specific inputs or ports , which are usually located on the rear of the system unit.

Interior of a computer cabinet

The different types of cabinets are:

  • ATX or Mid Tower (only for ATX or smaller motherboards)
  • E-ATX or full tower (for any size motherboards and components)
  • Micro-ATX, Mini-ITX or mini tower (only for motherboards of this size)
  • SFF (slim towers that stand in cabinets)

Learn more about the computer cabinet in this article: What is a computer cabinet?

CD, DVD and Blu-Ray drives

There are computers that are factory-equipped with a  CD, DVD, or Blue-Ray drive .

But in some cases they lack this component, since over the years it has been replaced by devices much less complex to use, transport and care , such as pen drives and memory cards, or even by storage in the cloud.

However, they are still widely used, especially in notebooks, and this type of unit can even be attached externally to the PC case.

CD, DVD and Blu-Ray drives

In general, optical storage units  use lasers to read and write data from a CD, DVD or Blu-Ray .

The first of these units to appear on the market was the CD units, which was followed by the DVD, about which you can learn more in this article: All DVD: Types. History. Care .

Then Blu-Ray appeared, which was a sensation among users due to the large storage capacity they could offer. Learn more about Blue-Ray in this article: What is Blu Ray? Capabilities


We all already know what a mouse is. But to define it we could say that it is a small device  used to point and select items on the computer.

You can find different types of mouses . Those that are connected by cable and wireless, but also those that have two buttons and a wheel, or that are full of buttons and allow you to get a better experience when playing.

Computer mouse

Mice are classified as follows:

  • Mechanics
  • Opticians
  • To be

When you move the mouse by hand,  an existing pointer on the monitor moves in the same direction .

So when you want to select an item, you just have to point to the item and press the main button . 

Different types of computer mouse

In short, point and click with the mouse is the main way that allows you to interact with the computer.

Do you want to know more about your computer mouse? Visit this article: The mouse or computer mouse


The keyboard is mainly used to type texts on the computer .

Like a typewriter keyboard, the computer keyboard has letter and number keys, but it also has special keys including function, number, and navigation keys .

Computer keyboard

Keep in mind that both the mouse and keyboard are considered the main input peripherals.

Learn more about keyboards in this article: Types of Computer Keyboard


The monitor  presents information visually, using text and graphics .

The part of the monitor that presents the information is called the screen , and like a television screen, a computer screen can display still or moving images.

Computer monitor

There are three basic types of monitors:

  • CRT monitors (Cathode Ray Tube or cathode ray tube)
  • LCD monitors (Liquid Crystal Display)
  • LED monitors

Keep in mind that while they all produce sharp images, LCD and LED monitors have the advantage of being much thinner and lighter.

Now, to know which of them is better, we invite you to read this article: The useful life of an LED or LCD TV


Basically, a printer transfers data from the computer to paper.

Therefore, keep in mind that you do not need to have a printer to be able to use the computer .

Anyway, if you have one, you can use it to print all kinds of digital content , including those photos you have chosen for the picture frames you bought.

Computer printer

There are three main types of printers:

  • Inkjet printers
  • Laser printers
  • 3d printers

If you want to know more about this, visit this article: Types of Printers. What is a printer?


With a scanner connected to your computer you can convert paper documents to digital .

But how is this?

Very simple, the scanner converts printed images into documents in digital format through the use of light.

Multifunction Printer with Scanner

Even today you can find scanners that capture objects in three dimensions .

Of course, the most used are the so-called multifunction printers , which not only have a printer but also a scanner.

Speakers or speakers

Speakers are used to reproduce sounds.

They can be integrated into the system unit or connected to it via cables .

With them you can listen to music and the different sound effects produced by the computer.

Computer speakers

Please note that these devices are considered as output devices .


With the microphone, your voice basically enters the computer as information .

How does this happen? Because the microphone is an electroacoustic transducer . This means that its function is to translate the vibrations due to the atmospheric pressure exerted on its capsule by sound waves into electrical energy.

Thanks to this, you can not only record all kinds of sounds on the computer , but you can also converse in video conferences.

Computer microphone

Depending on the quality of the microphone you use, the quality of the sound obtained will of course vary.

So if you want to know how to achieve excellent quality, we recommend this article: How to Record Audio with quality. Step by step instructions


It is a small digital camera that connects to the computer . With this you can capture images, which you can later transmit over the Internet .

Surely you have used it more than once for video conferencing, and without a doubt web cameras are very useful.

Computer Webcam

The notebooks often include a webcam as a small lens into the surface of the casing, next to the screen.

But if you have a desktop computer, you can easily add an external webcam to it . For that you will find the most varied models on the market.

To learn more about the different types of webcams, visit this article: What is a webcam: Computer camera


In order for you to have an internet connection on your computer, you need a modem.

A modem is a device that sends and receives information over a high-speed telephone line or cable .

In addition, routers or modems are considered as hybrid peripherals , since they allow the input and output of data.

Internet modem

Learn more about this component in this article: Differences between Hub, Switch and Router

In addition, in order to have Wi-Fi internet with a good signal throughout the house, it is best to use Wi-Fi repeaters.

Learn more about it in this article: The art of the WIFI REPEATER

Video game controls

Video game controllers are what you usually connect to the computer to be able to precisely control the movements and actions when you are playing .

Although you can use a mouse and keyboard to do this, the experience provided by the controls is extraordinary. So if you like to play video games, this component cannot be missing.

Computer joystick

There are several types of video game controls , the most commonly used are:

  • Gamepad
  • Joystick
  • Steering wheel
  • Pistols

Glasses and accessories for virtual reality deserve a separate paragraph, on which we recommend you read this article to learn more about it: Virtual Reality: Characteristics, objectives and history. Lenses and games

MIDI controller

MIDI stands for Musical Instrument Digital Interface .

MIDI controllers connect to your computer and allow you to play or record sounds . They allow you to trigger sounds stored in hardware or musical instruments emulated by software, better known as VSTs .

The best known are MIDI keyboards with keys just like a common keyboard, although you can also find models that have buttons .

MIDI controller

These can also be used to control functions within the program in which you are using it.

If you are interested in MIDI, then surely you want to know how to have your own recording studio. Learn more about it in this article: Build your home recording studio

Internal components

We have already reviewed what are the internal components of a computer. Now join us to see what is inside.

When we talk about a computer we also refer to the set of internal components that are located inside the cabinet.

As you know, the internal components are what make up the hardware of your PC . They are the ones who handle the information you enter or download from the internet.

Internal computer components

The main internal components of the computer are:

  • Base plate
  • CPU or processor
  • RAM
  • HDD
  • Graphic card
  • Power supply
  • Network card

In addition, in general, to prevent the heat generated by these components from accumulating inside the cabinet, other elements are added that are also considered internal components.

These might be:

  • Heatsinks
  • Fans
  • Liquid refrigeration

You rarely open your PC case to inspect what’s inside. So if you want to know more about it, we invite you to read this article: What components does my PC have? How to use Speccy to find out

The processor or CPU

The CPU is something like the brain of your computer . It is actually the element in charge of analyzing all the information that enters and leaves the PC .

Computer processor

In general, the processor decodes and executes the instructions of the programs that are loaded in the main memory of the computer .

It also functions as coordinator and controller of almost all the other components , both internal and external.

Due to its mission within the PC, the processor is the one that defines the process speed that the computer achieves . The higher the amount of GHz, the higher the speed will be.

In terms of brands, the best known in the current market are Intel and AMD .

But in addition, the processors can be:

  • 32 bit
  • 64 bit

Most processors are factory fitted with a fan to keep the component cool.

Learn more about this in this article: The computer’s processor

Base plate

Without the motherboard, a computer could never function .

The different internal components are connected to it , including the processor, the RAM, the graphics card, the hard drives, that is, all the internal elements.

Computer motherboard

In form, motherboards are built on a PCB board that contains an integrated circuit that interconnects a set of chips, capacitors, and connectors.

Depending on its format , a motherboard can be:

  • XL-ATX and E-ATX
  • ATX
  • Micro-ATX
  • ITX

In addition, within a motherboard the following components are already incorporated from the factory :

  • BIOS
  • Sound card
  • Network card
  • Expansion slots

You must bear in mind that not all motherboards are the same. Therefore, the one your computer uses must be compatible with the processor and components .

Computer motherboard parts

Bear in mind that ultimately  the motherboard is the one that will determine the type and quantity of RAM modules that can be installed, the amount and types of hard drives that are connected and the video card that you can mount on it, among other things.

To learn more about the PC motherboard, visit this article: The motherboard of a computer


The Random Access Memory or better known as RAM memory is connected to the motherboard and in it the instructions that are executed in the processor are saved and loaded .

These instructions are sent from the components and devices connected to the motherboard and to the ports of the PC.

However, keep in mind that the data is first stored in the so-called cache memory and then passed to the processor .

An important fact is that this data is not permanently recorded as it happens with the hard disk, but it is erased every time you turn off the computer .

Computer RAM

The main characteristics that define how RAM memory works are:

  • Amount of memory in GB
  • RAM memory type
  • Memory speed
  • Groove type

It is important that you are clear about these data to choose the correct type of RAM for your computer. Ultimately, the motherboard will be the element that defines the type and amount of RAM  that you can install.

If you want to know more about the different types of RAM memory, we recommend you read this article: RAM memory

Important: Do not confuse RAM memory with ROM memory. To know more about it, visit this article: What is ROM? What is it for? Types


Your computer’s hard drive is the component in charge of permanently storing the data that enters the PC.

Everything you have on your PC , including documents, photos, your music, the things you download from the internet, are stored on your hard drive .

But in addition , the operating system and all the programs installed on the computer are also stored in it.

Computer hard drive

In order to be the primary storage medium for your computer, the hard drive can contain large amounts of information.

Keep in mind that ultimately,  all computer data is stored on the hard drive, hence its importance.

Therefore, when you go to buy a hard drive you should keep in mind the following information :

  • Capacity
  • Connection speed
  • RPM speed

Regarding the type of connection they require , hard drives can be:

  • SDI
  • SATA

In addition, today there are different types of hard drives, which differ depending on the technology used for their construction. Today you can find the following types of hard drives:

  • HDD (traditional mechanical disk)
  • SDD (solid state disk)

SSD type hard drive

It is also important to note that in recent times traditional hard drives are being replaced by modern  Flash memory type storage units.

These flash memories do not emit heat or noise , they do not wear out over time and they are really fast.

Learn more about your computer’s hard drive in this article: The hard drive or hard drive

In case you want to know more about flash memories, we invite you to read this article: Flash memories

Graphic card

The graphics card, also called a motherboard or video card, is a device that connects to the expansion slot of the motherboard.

It includes a graphics processor or GPU , which is responsible for processing computer graphics .

The truth is that in general the graphics card is not included in the PC, since most motherboards include a circuit capable of handling graphics processing at the factory .

However, they are a component that you can often require, especially if you handle large graphics, for example to play video games .

Computer graphics card

Keep in mind that the graphics processor of a video card is much more powerful than those that motherboards usually include. In addition, it acts as an independent RAM memory , improving visual processes.

Of course you must bear in mind  that the video card is compatible  with the motherboard, that is, the interface for communication between both elements is  AGP, PCI or PCI-e.

Learn more about graphics cards in this article: The Computer Video Card

Power supply

As the name implies, the power supply is the component that provides electrical current to all elements of the computer. This is inside the cabinet.

To do this, the power supply transforms the alternating current from your home network into direct current . After that, it distributes it to all the components that are connected to the PC.

It is important to note that power supplies usually handle 12V, 5V and 3.3V.

Computer power supply

Keep in mind that the most important data in a power supply is the power it delivers . In this case, the higher the power, the greater the capacity to connect components.

In general, a power supply can have a power of 400W to 500W , although for computers that have additional hardware, such as a video card to play video games, a 700W source is recommended as a minimum . The best is a source of more than 1000W.

There are also different types of sources :

  • ATX (compatible with ATX, Mini-ITX and Micro-ATX cabinets)
  • SFX (compatible with Mini-ITX enclosures)
  • Server format (for server cabinets)
  • External power supply (transformers like those included in notebooks)

Network card

In general, computers usually include the network card built into the motherboard of the same. That is why it is not surprising that you ignore its existence.

In the event that your computer does not have a network card or has broken down, you can always add a new one through the PCI-Express x1 slot .

Computer network card

The network card is basically the one that will allow you to connect to your router to be able to use the internet on the PC.

They are known as expansion cards and there are two main types of them:

  • Ethernet : For wired internet connection
  • Wi-Fi : For wireless internet connection

To learn more about this important component of the PC, we recommend you read this article: What is a network card? Types

We also invite you to read the article about WiMax, the platform that allows you to use the internet anywhere on the planet: WiMax: What is it? How does it work? Profits

Heatsinks and fans

Although it is not necessary for your computer to have a heatsink, this is an element that can save you several headaches.

In general, a heatsink collects the heat generated by a component and dissipates it to reduce the temperature of that electronic element. It is very common to see them with the processor.

Computer fans

In addition, the internal cabinet fans , which serve the function of maintaining a constant air flow inside the cabinet.

If you want to know more about the cooling systems of the computer, visit this link: Cooling Computer

Keep in mind that there is also a system to maintain the temperature of the PC called liquid cooling.

Computer cooling with liquid nitrogen

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