Components of a computer

In layman’s terms,  a computer is a computer system made up of various electronic components  that 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.

In this article we will know a little more about the hardware and the functions that each of these components fulfill within the PC, in addition to knowing how to recognize the basic differences between software and hardware . Also for those more daring, we will talk about the internal components that we need to build our first computer.

Hardware and software

First of all, we must know that a computer is basically made up of two basic aspects: Hardware and software, whose differences we will know from this point on.

Computer hardware

Computer hardware can be defined as all those physical or material parts that we can see and touch. For example,  monitor, keyboard, mouse, hard drive, cabinet, and so on . That is, the device itself with its internal and external parts.

In a simple way we could define the computer as a box to which a series of devices known as input and output peripherals are connected , which serve to enter and extract information. The box we refer to is the brain of the computer and is where the information is processed.

Computer software

In very general terms we could understand software as the set of instructions that computers use to manipulate and process data. Without software, the computer would be  a set of physical devices without any use , just as our body would be without a brain that would tell it what to do with arms, legs, mouth, and other limbs and organs.

System software is a type of application that allows the information processed by production or application software to be transformed into understandable instructions for the hardware components. In other words, its function is to communicate the hardware elements with the different programs that we use to execute specific tasks. This category includes, for example, device drivers and operating systems.

Currently, the most used operating systems are:

  • Windows
  • Linux
  • Android
  • MacOS
  • iOS

Components of a computer

From this point on, we will mentally disarm a computer to learn more about all its internal components.

System unit or cabinet

The system unit or cabinet  is the core of a computer system . Typically it is a rectangular box. Inside this box are many electronic components that process information. The most important of these components is the CPU (central processing unit), or microprocessor , which functions as the “brain” of the computer.

Another component is  RAM  (Random Access Memory), which temporarily stores the information used by the CPU while the computer is being used. The information stored in RAM is erased when the computer is turned off.

Virtually all other components of a computer are wired to the system unit. The cables are connected to specific inputs (ports), which are usually found on the back of the system unit. Hardware that is not part of the system unit is sometimes called an external or peripheral device.


The computer has one or more disk drives (devices that store information on a metal or plastic disk). The disk stores the information despite the computer being turned off.

Harddrive unit

The computer’s  hard drive stores information on a hard drive, a disk, or a stack of hard drives with a magnetic surface . Since hard drives can hold large amounts of information, they usually serve as the primary storage medium for the computer,  storing virtually all programs and files. The hard drive is normally located inside the system drive.

CD, DVD and Blu-Ray drives

Virtually all computers today are equipped with a CD or DVD drive , typically located on the front of the system drive, optical drives  use lasers to read and write data from a CD, DVD, or Blu-Ray . If we have a recordable disk drive, you can save copies of the files on blank optical media. It is also possible to use the CD drive to play music CDs on the computer.

DVD drives can do everything CD drives do and, on top of that, they can read DVDs. If we have a DVD drive, we can watch movies on the computer. Currently all DVD drives can write data to blank DVDs.

If we have a CD or DVD burner drive,  we can periodically make backup copies of important files on CDs or DVDs. In this way, if the hard disk fails or breaks, we will not lose data.

As for  Blu-Ray drives , these are more modern and therefore not as widespread on the market, but may be able to store up to 50 Gb of data on a dual-layer disk.


The mouse is a small device  used to point and select items . Despite the fact that the mouses have various shapes, the typical mouse has an appearance that resembles a mouse, hence its name. It is small, rounded, and connected to the system unit by a cable. Some more modern mouses are wireless.

Typically, a mouse has two buttons: the primary button (usually the left button) and a secondary button. Many mouses  also have a wheel between the two buttons, allowing easy movement of the button .

When you move the mouse by hand,  an existing pointer on the monitor moves in the same direction . (The appearance of the pointer may change, depending on the positioning on the monitor) When you want to select an item, you only have to point to the item and click (press and release) the main button. Aiming and clicking with the mouse is the main way to interact with the computer.


The keyboard is mainly used to write texts  on the computer. Just like the keyboard of a typewriter, the computer keyboard has keys with letters and numbers , but it also has special keys:

  • The function keys, located on the top line, perform different functions depending on the way they are used.
  • The numeric keypad,located on the right side of most keyboards, allows you to enter numbers quickly.
  • The navigation keys,such as the arrow keys, allow you to change the positioning in a document or web page.

It should be noted that both devices are considered input peripherals.


The monitor  presents information visually, using text and graphics . The part of the monitor that displays the information is called the screen. Like a television screen, a computer screen can display still or moving images.

There are three basic types of monitors: CRT (Cathode Ray Tube, now almost obsolete), LCD (Liquid Crystal Display) and LED monitors. All types produce sharp images,  but LCD and LED monitors have the advantage of being much thinner and lighter.


A printer transfers data from the computer to the paper. It is not necessary to have a printer to use the computer , but if you have one, you will be able to print email messages, cards, invitations, announcements and any other material. Many people also take advantage of being able to print photos at home .

The two  main types of printers  are inkjet printers and laser printers. Inkjet printers are the most widely used printers. These printers allow you to print in black and white or color and can print high-quality photos using special photo paper. Laser printers are faster and better withstand more intensive use.

Speakers or speakers

Speakers are used to reproduce sounds. The speakers can be integrated into the system unit or connected to it by cables . The speakers allow you to listen to music and the effects of sounds produced by the computer.

It should be noted that these devices are considered as output devices.


To connect the computer to the Internet, you need a modem. A modem is a device that sends and receives information over a telephone line or high-speed cable . Modems are sometimes built into the system unit, but they are not the fastest. Currently,  these types of devices are no longer used , being replaced by modern external ADSL or cable modems, which also incorporate Router features . Routers or modems are considered as hybrid peripherals, since they allow data input and output.

How to build a PC: basic components

We all know that there are two great alternatives when purchasing a new desktop PC: on the one hand, go to the appliance store and choose some of the available pre-assembled models, and on the other hand, buy a computer supplies house every one of the parts that will make up the new equipment, and then assemble the PC with our own hands.


If we roughly evaluate both options, we will immediately notice that buying components and assembling the computer by our own means will have a remarkably reduced budget compared to an assembled PC, since in that case we are not really paying the labor of a technician. .

Such is the difference in money that even with the budget we had available to buy an armed PC, we will be able to acquire significantly more equipment if we decide to assemble this PC with our hands . Of course, for this we need the time necessary to carry out the assembly as appropriate, so if we do not have that time available, the best thing is that we stop reading now and go to the store to buy the pre-assembled computer.

For those who continue reading, we tell you that from this point on we will try to provide all the necessary information to build a PC that not only works, of course, but also allows us to overcome even our production needs.

It is important to mention that  to carry out the assembly of a desktop PC it is not necessary to have a deep knowledge about the operation of the different components that will be part of the equipment, but it is essential that all the elements are compatible and placed in the correct shape inside the cabinet.

Choice of necessary components

From this point, we will move on to one of the most significant aspects,  the choice of components to build our PC. In this case we will start with the processor, the heart of every PC.

Choosing the processor

In the first instance we must choose the CPU,  that is, the processor of the computer. Only once we have decided which processor will we want to use, can we begin with the selection of the other components.

Keep in mind  that the processor is the one that will define the processing speed that the PC will offer,  so it is a more than important point to opt for the highest possible number of GHz depending on our budget.

In the event that we want to use the computer to run games or perform video editing, for example,  then we will have to overcome the 2 GHz barrier widely, being the most recognized brands Intel and AMD.

We must also evaluate whether the processor will be 32-bit or 64-bit. In this sense, the basic differences that exist between the two are that a 64-bit system carries out a different type of process management than that of the 32-bit system, which often makes it faster 64 bits.

On the other hand,  while the 32-bit only supports up to 4 Gb of RAM, the 64-bit allows more RAM,  so ultimately this choice will depend on the amount of RAM we want our team to have.

Another important factor is the cooling of the element. Currently  most CPUs include a built-in fan,  but in the event that we buy a processor without a fan, we must purchase a separate cooler and thus keep the component well cooled.


One of the fundamental aspects that we must take into account when choosing  the motherboard  is that it is fully compatible with the processor and the components that we plan to include.

Keep in mind that ultimately,  the motherboard will determine the type and number of RAM memory modules that we can incorporate,  the number and type of disk drives that can be attached, in  addition to the video card that we can mount on it.


The amount of RAM memory will depend directly on the type of requirements that we want,  so in principle we should evaluate what we will use the computer for, since we take into account that if we are going to run high-end applications on it, we must have a lot of RAM memory.

In the case of a basic PC, for simple tasks and applications that do not require too many processes,  at least we should opt for a DDR3 type RAM, of at least 2 Gb,  although with this it will not be perhaps as fast as we expect.

As an example, keep  in mind that although Windows 7 officially requires at least 1 Gb,  the truth is that in order to run the operating system correctly, at least 2 Gb are necessary.

As for memory, we must always keep in mind that the motherboard will ultimately be the element that defines  the type and amount of RAM that we can install.

Hard disk

When we talk about a hard disk, the first thing we think about is storage, and although that is its main function, it also fulfills other processes that we must take into account when choosing the component.  In short, all the data from the computer is stored on the hard disk , so when selecting which one to buy we must evaluate its capacity, the connection speed and the RPM speed it provides.

Regarding its capacity, this is a point that will depend on the storage requirements that we need,  for example, if we are affected to collect movies and series on the PC, it will be necessary to have a disk with a large capacity.

In any case, at present  the basic thing would be to have a hard disk of not less than 160 Gb of storage capacity. But the type of connection it provides is also important.

At this point, it  is recommended to choose a SATA hard drive because the IDE format is no longer manufactured,  and also because SATA is currently the standard in the market, mainly due to the speed of access to the data that it provides in comparison to other old technologies. Of course, our motherboard must have SATA connectors so that we can incorporate this type of disk.

Video card

When we are faced with the choice of the video card, we must bear in mind in principle that currently most of the motherboards on the market have an integrated video card that can be more than enough for those who want to build a PC with requirements basic.

But the truth is that if what we need is a computer that allows us to carry out  other more complex processes such as games,  then we should start looking for a suitable video card.

The minimum that we must acquire is a video card  with a capacity of at least 1 Gb. Of memory,  if it is more better, since although it is true that memory does not increase the speed of the computer, the truth is that it acts as independent RAM memory, improving visual processes.

As for brands, undoubtedly the best are NVDIA or ATI, or one of the owners such as XFI. Of course, we must always take into account  that the video card is compatible  with the motherboard, that is, that the interface for communication between both elements is AGP, PCI or PCI-e.


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