How Does a Computer Work?

A computer is an electronic machine that has the ability to input, store, process and output information or data. Computer has its roots back in the 19th Century.

An invention of the English mathematics professor Charles Babbage of the Analytical Engine opened the path for the invention of the computers because the designs of the Analytic Engine form the basic framework for computers today.

It is also important to note that the first electronic digital computer was built by DR. John V. Atanasoff and Clinton Berry.

It was called Atanasoff-Berry Computer (ABC) The foundation of the idea of computer is in the numbers. Having been created as a gigantic calculator, the improvement of the computer heavily borrows on the principle of arithmetic.

For example, if someone was writing a word document, and they want to magnify the font by let’s say ten, the computer will magnify each pixel on the page by ten by multiplying the pixels by ten.

Mirroring a photo image would mean inverting the arrangement of the pixels for example either right to left or left to right.

Whereas the computer is composed of two main parts namely the hardware and the software, its basic functions are carried out at the Central Processing unit (CPU. After data has been input into our computers, the CPU takes over the work of processing the data.

This is a highly complex electronic process involving numerous circuits which execute commands from already installed programs. When the processing is done, data is sent from the CPU to the output devices.

Computer Hardware

Data Input

Computers could not make any much sense if there was no way of inputting data into them, even the first gigantic computers which were merely for calculating had some means of inputting data into them.

Today, the keyboard, mouse and microphones are some of the devices used to feed computers with information.

Data Storage/Memory

Computers storage is divided into two:

  • Internal Memory

Internal memory also called the internal hard drive is a hard drive (Internal because it is always inside the machine itself) that stores the operating system and other files and programs. An operating system is a program that controls the general functioning of all parts of the computer.

  • External Memory

External Memory are removable storage devices that a computer user may choose to store data in. These may include flash drives, SD memory cards, removable hard drives and many others. Digital revolution has nowadays introduced cloud computing as a means of external storage too.

Data Processing

The Central Processing Unit is the processor of the computer. However, it does this by the use of a microchip embedded on the motherboard of the CPU. This microchip is called the Processor.

It is usually tiny and can heat up after working for long periods of time hence the need for fans in every CPU to cool down the processor. Fans become an important part of the computer because the computer needs to get rid of the excess heat being generated in the process of data processing. Without the fans, the computer can literally burn to ashes.

Data Output

Data output includes the delivery of processed data and output devices include the monitor screen, loud speakers, printers. An illustration of this could be, when someone takes brilliant pictures at a picnic and feeds them into the computer from the mobile phone, the phone becomes the input device and the pictures get stored in the internal hard drive of the computer.

The person who fed them into the computer will view the photos through the monitor of the computer. The monitor then becomes the output device.

Computer Software/Programs

Any input action to the computer is like an order. By just pressing a key on the computer keyboard, you have ordered the computer to do something. This ‘order’ is called a command. Commands start up the process of computer functioning by ordering the programs to make the computer to carry out a specific duty.

A program is simply a set of commands put together so as to enable the computer to perform a series of specific functions (simple or complex) by itself once the command has been given.

The innovation of programs has perfected the computer so much so that the computer has immensely reduced in size while steadily perfecting its functionality.

There are some basic functions of the computer that most people might want to use many times. Program manufacturers such as Microsoft and Macintosh among others thought it wise to make a master software with all basic computer functions so that all other programs could be mounted on the master program.

The master program is called the operating system. Some of the most common ones include Microsoft, Macintosh and Ubuntu.

BIOS (Basic Input Output System) is the link between the operating system and the hardware and therefore the operating system heavily relies on BIOS to ensure that the commands made are executed by the hardware.

BIOS is a program written by the manufacturer and stored in one of the computers main chips. It is called firmware.

Basic Parts of a Computer

As earlier discussed, a computer is a combination of hardware and software that make up this wonderful machine. The hardware is a combination of physical electronic components performing different tasks.


A monitor is an output device used for displaying all function that need to be seen.

Such may include word files, video files, photo files and many others. Monitors come in different sizes and qualities including the LCD monitors.

Hart Drive

As mentioned above the hard drive is a storage/memory device used to store all files including program files.

Central Processing Unit (CPU)

Central Processing Unit is a processing device and a unit of the computer on with a microchip processor to enable the processing of data or information. Like the name suggests; it is responsible for processing any information

The CPU is divided into the following two components:

  •  The Control Unit

This section has circuits that use signals to tell the computer what to do. Instead of doing the operations by itself, the control unit communicates with other parts of the computer system and delegates duties.

  •  The Logic/Arithmetic Unit

It has circuits which are responsible for the execution of logical and arithmetic operations. It can execute four different mathematical operations namely addition, subtraction, division and multiplication.

Logical operations in a computer are based on comparing numbers, special characters and also letters, after which the system reacts in accordance with the comparison results. For instance, it can be able to tell the winner of a contest by comparing the marks warded or the votes.

Random Access Memory (RAM)

This is a computer location where all files in current use are stored, the files in current use at any particular time may include; operating system, application programs and data.

However, the contents of the RAM are fairly temporary are they are lost the moment the computer is turned off. The bigger the RAM, the faster the computer.

Read Only Memory (ROM) and Bios

Read Only Memory (ROM) chips are found on the motherboard. It contains information directly accessed by the processor.

Data transfer in ROM is faster than in any disk. The information in the ROM that controls the basic input and output procedure is the BIOS.


The motherboard is the main circuit board that ties everything together. It is main because it is the basic power and communication distributor.

The performance and running of the computer heavily depend on the ports and compartments of the computer. Only components connected to the computer will be recognized by the computer.

Sound and Video Card

Sound and video cards are output devices containing circuits allowing computers to play sounds as well as displaying graphics. These are also very important items.

For example, a music recording studio will require a very powerful sound card given the fact that their main aim of having a computer in the studio is to improve the quality of sound.

Video editing studio should as well have powerful graphic card to improve the quality of video editing process by improving the video visual appeal always.

Power Supply

Power supply converts your home or office power voltage. The power supply allows for the use of computers by various power consumers across the globe. The power supply has a 110 v mark and a 230v one.

Choose what is appropriate for the country you come from. Most part of the computer are replaceable, and the power supply is not an exemption.

Due to the virtue of its work, the power supply becomes very hot. So, it is mandatory for the power supply, just as the processor, to have a fan to cool it down.

External Connections (Ports)

It is possible to connect your computer to an external source for example printers, external hard drives, flash drives and webcams either through a cable connection or a wireless connection.

Nowadays computers have been standardized to the extent that there is a standard way of linking devices through the Universal Standard Bus (USB)

Program and Software

Computer programs are a collection of commands put together and installed into a computer with an aim of making the computer perform specific functions when those commands are inputted.

It is important to note the difference between programs like Operating system, Basic input Output System and other application programs. The operating system is a very special type of program.

It is the mother program that creates suitability and compatibility for all other programs. The operating systems ensures the harmony that makes a computer user listen to music as they view photos. It is the mother of efficiency and multi-tasking in all computer devices.


Most PCs have one or more drives, either CD or DVD writer or reader. Although most PC manufacturers are making their own motherboards, most components used are standardized. It is not surprising however to find a Samsung component in a Lenovo computer because companies nowadays agree to such arrangements.

Precautions on Using the Computer

Computers emit a lot of light at full brightness, so it is important for the users to regulate the brightness of their monitor screens.

Being an electronic devices, computers should be handled without damp hands to avoid the risk of spoiling the device and the risk of electrocution too.

These gadgets are expensive and therefore they need special care.

It is very important to ensure you install an antivirus program to your computer if you are a regular internet user because the internet has a lot of viruses that could cause malfunction in the device.

Other than just installing the antivirus, it is very essential to patch or update the programs in the computer as regularly as possible so as to mitigate the risk of virus or malware attack.

Apart from the all that work that computers help with, there comes the risk of hackers who place malware into the computer to help then get essential financial information to help them rob you.

It is advisable to have all vital information kept separate from the computer if the user is a financial operative.

Final Thoughts

Computers have revolutionized the world by replacing man in most of the things that would otherwise require his presence.

Computers now control most aspects of running of the world. Nuclear power and weapons have their foundation on computers.

Almost every sector in the globe now depends on computers. Today, computers have been transformed into very many helpful gadgets that make man’s life more and more comfortable by the day.

Very sensitive sectors like the medical sector, transport sector, security sector and many others that require critical attention are heavily dependent on the computers.

It is fundamental to know that the basic functions of a computer are to input, store, process and output data or information.

A computer is an electronic gadget made of hardware and software. The software is merely for giving commands to the hardware through the BIOS on specific functions to be performed by the computer and the hardware provides a platform for human interaction with the machine.

It is one of the main gadgets that enabled man travel to space. To date, no space venture is possible without the computers.

About the author


Geek Life Activated is my little corner on the web. I'm very passionate about tech, and i aim to use this blog to express that. I currently work as a System Administrator, and i love every second of it. I'm still new at it, so i'm learning something new everyday. I'm pretty open to learning new things, so please feel free to correct me if i'm wrong about anything, and you can contact me anytime you want. I'm a very easy person to talk to. :)

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