What is inside a computer?

For a full history of how computers (calculators) have been created please read the two following books:

To make it simple, computers have been created in order to make complex mathematics that a brain cannot perform. So the basic idea is that computers are doing mathematics and thanks to those can run programs (any of them, from a video game to a text editor, to run a social network...)

Ok so you have a computer in front of you, but do you have any ideas what’s in it ? Is it a good computer? Is it a bad one? That's what we are going to see within this part.

A computer whatever it is (laptop, smartphone, printer…) is composed of two things:

  • Hardware (physical components).
  • Software (which represents the programs which are within the computer).

For the moment, we will stick with the first category, the hardware. Mainly, a computer is composed of the following hardware components :

  • Central unit if you are using a desktop, which contains all the elements below. For a laptop the central unit is your laptop in itself, it is just that components are smaller.
  • Battery (if you are using a laptop or a smartphone) you don't have batteries on desktops as it won't make sense.
  • Screen, also named monitor. (always adapt the light of your screen according to the one outside. So you shouldn't have a huge contrast between the two). Do not have lights in front or behind your screen.
  • Hard drive.
  • RAM.
  • Processor.
  • Motherboard or Main board.
  • (optional) Graphical card
  • Mouse (in laptops their are merged with the keyboard, on smartphones your hand or pen is your mouse). Vertical mouses may be more comfortable.
  • any other connections. In fact all those peripheral components are sometimes referred as input/output source. For example when you plug to your computer a keyboard, it is an input source, data will be sent thanks to this keyboard. When you plug a screen, well this in an output, data are sent from the computer to the screen. In some cases, you may not have to plug your components physically but can use different wireless connections such as Bluetooth, wifi, nfc... Each of those components will be plugged through different ports, to name a few: power supply, hdmi, vga, usb, audio, ethernet...

Important notice: laptops are very bad in terms of health. In order prevent a bad use of a laptop here are some pieces of advice. Always have a separate keyboard and mouse (if not your hanks will not work freely). The screen of your laptop has to be at eye level. Your laptop has to be on a stable plan, not on your knees. Take some breaks (every 30 minutes is a good basis) and during this break do not look at a screen for about a minute. Sit properly with good support for your back. Pay attention as well to not block the fans, if not the temperature of your laptop will increase and it may burn your main board. A good distance between your eyes and your screen is 50 cm to 70 cm.

Let's now see each of those components individually.

A laptop motherboard

By Ravenperch at English Wikipedia - Own work (Original text: Self created), CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=18540450

What is a hard drive ?

A hard drive is nothing more that the number of files/data you can host on your device. Imagine it like number of cube meter your house can contain. You can store stuff up to a certain point when even an ant could not enter within your house.

What size my hard drive should have? Well, it depends of the use that you have of your computer and how technologies are evolving. Let's take an example, some years ago, having a 10 Go hard drive was extraordinary, why? because videos were not that widespread. Right now in 2019, making videos is going mainstream, a simple 5 minutes video can take about 300 Mo, so you can imagine that a 10 Go hard drive will soon be insufficient for this use. Currently in 2019, purchasing a computer with 500 Go or 1 To is reasonable.

Hard drive is something which is scalable, so if your hard drive does not have enough memory, you can purchase and plug a new hard drive and/or you can purchase an external hard drive. So to say, don't throw your computer away if there are no space anymore, there is always a solution to find.

What is a processor ?

The processor is the strength of your computer. The more powerful it is, then the more complex calculations it will be able to handle. By calculation we mean actions the computer can accomplish. To make it simple, imagine that you are browsing the internet and are using Mozilla Firefox. With a weak processor, you will probably start to struggle when loading just a web page, whereas decent laptops will handle a dozen of web pages open as tabs without any issues.

Processors are melted to the motherboard, so to say, if your computer has a weak processor, this is over. This is not a component that you can unplugged and changed as you wish.

The strength of a processor is defined in Ghz, let's make a comparison of products to make that easier to understand:

Processors comparison
Computer name
Raspberry Pi 2
Samsung Galaxy A10
HP Pavilion 15-cs3011nf
Processor 900MHz
1.6GHz, 1.35GHz

Once more the higher the Hz are the more powerful the processor is.

What should be the right processor for your use? Well, you have to identify what is the most complex action you will require your computer to perform. Once done look at the software which is demanding the most to your computer and have a look at their requirements. You will then know if it is adapted or not.

What is RAM ?

RAM is here in order to help the processor make the mathematics for the programs which are ran. It stores the temporary and necessary information for the programs you are running. The more RAM you have the more mathematics your computer will be able to do.

What is a motherboard ?

The mother card is card on which all the components are melt on (that the case of the processor), some others can be clipped on it, that’s often the case with the RAM for example.

What is a graphical card ?

As its name stand for it, it allows the information to be displayed on your screen.

In general processors and RAM are enough in order to run most of software, but in some cases, the effort requested in order to run a software are so high that it needs another component to improve the calculations processes. This is where the graphical card comes in handy. A graphical card is mainly used for games, 3D applications, blockchains everything which require complex calculations.

So to say the more complex the calculations you will make will be, the most expensive those components are going to be.

Thanks to the possibilities offered by the mother board, you can add many connectors to your computer, a non exhaustive list is :
    • VGA/HDMI screen.
    • Keyboard.
    • Microphones.
    • Printer.
    • CD/DVD reader.
    • …

CPU: Central Processing Unit. The CPU is the brain of every computer. The more powerful it is the fastest the calculations will be so the fastest your computer will run.

RAM: Random-Access Memory. Different types: DRAM, DDR2. The RAM is the partner of the CPU. What does a CPU do? It process data, those data have to be stored somewhere, in general this is the hard drive. Though requesting and processing data from the hard drive takes time. That's the reason why the RAM is here. The RAM is here to store temporaly some data in order to make them accessible faster for the CPU. Data stored there are temporary. The more you have the better it is.

Motherboard: this is the board which is "hosting" the main components of your device this is why we call it the motherboard for main board. Without it your components could not be connected with one another. This is an electronic circuit.

Hard disk: Where your data are stored. The more you have the better it is.

Graphical card: responsible for what is displayed on your screen.

Is a smartphone a computer?

The answer is yes, it is nothing more than a device with a GPS and a phone component plus any additional components which wouldn't make sense to add to a traditional computer. Technically you could add a keyboard to a smartphone and also share its screen with the one of a computer, you would get what one call a real computer.

If you are having trouble to read the serial number of spare parts, take a picture and use a zoom to see what is written;
A hard disk and its processor
Last modified: Monday, 3 August 2020, 2:21 PM