How Does A Computer Work


How a computer functions is basically grouped into four operations; input operations, storage operations, data processing operations and output operations. These operations are totally based on the computer’s definition.

This section will throw more light on what happens from when a computer gets turned on.

  1. On pressing the power button, an efficient amount of electricity and voltage is supplied to the computer and its components. This is after the computer power supply converts the alternating current passed down from pressing the power button to direct current.
  2. Through transistors, a signal is sent to the computer’s central processing unit and motherboard.
  3. A power supply check (POST) is performed by the computer – This is basically how the computer ensures it gets adequate or efficient power supply after pressing the power button. A self-test commonly known as POST (Power On Self Test) is carried out by the system’s power supply unit. The Power On Self Test goes through the computer’s internal hardware checking for compatibility and connections, also ensuring everything is in check before launching the operating system for the user. After the Power On Self Test has been successfully completed, a bootstrap loader step is initiated by the BIOS to launch the operating system into the computer’s main memory which is the random access memory (RAM).
  4. BIOS is activated by the central processing unit (CPU) to begin the booting process – After the POST (Power On Self Test), the central processing unit (CPU) is responsible for activating the BIOS (Basic Input Output System) to execute the booting process. Basic Input Output System (BIOS) is a system utility program that assists the central processing unit with loading the operating system each time the computer is turned on. The computer user is ready to run operations after the operating system is fully operational.
  5. BIOS kick-starts the computer’s operating system.
  6. Before the user initiates a program launch, the installed operating system (e.g Windows 10) takes charge of the computer.
  7. The program executed is loaded into the main memory by the installed operating system – Here the computer’s operating system issues out the required resources (memory storage, RAM) for program launching by the user. An executed copy of the user’s program alongside other data is launched by the operating system into the random access memory (RAM). The computer’s operating system has the capability of managing memory required for running different programs by the user on the system. A virtual memory (a mechanism responsible for accommodating memory needed for programs that exceeds that of the random access memory) is used by the operating system.
  8. After that, the central processing unit (CPU) begins the program execution – The central processing unit is known to be the brains behind the computer system which is responsible for making ready the processing power needed by the computer system to function efficiently. The central processing unit (CPU) uses data and instructions from the random access memory (RAM) to kick-start program execution.
  9. The user’s command or data input is then stored in the main memory.
  10. The user’s processed data is then sent to the output device.

If you’re having issues powering up your computer or booting into an operating system, please get in touch with our computer technician.

I am a computer engineer holding a bachelor's degree in Computer Science, complemented by a Master's in Business Administration from University of Strathclyde, Scotland. I currently work as a Senior IT Consultant in Melbourne, Australia. With over 15 years of...