How Computers Work

Generally when people refer to the "computer" they look for a general-purpose machine built around a microprocessor. A computer can be used for typing documents, reading and sending emails, browse the internet and/or play games.


What are the main components of a typical desktop computer?

•  Central Processing Unit (CPU) - A lot of people refer to the CPU as the whole machine encased in a desktop tower. However, CPU is actually ,the brain, the microprocessor of the computer system. It is the single most important component of your computer as it oversees everything that is happening in your computer.

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  image from howstuffworks.com

  Memory - This is very fast storage used to hold data. It has to be fast because it connects directly to the microprocessor. It has different types, for different functions in the computer system. (RAM/ROM/BIOS/Cache/Virtual Memory/Flash Memory)
• Motherboard - This is the main circuit board to which all of the other internal components connect.
• Power Supply - The electrical transformer that supplies and regulates electricity for the computer
• Hard Disk - The large-capacity storage, usually more permanent storage of data.
• Operating System - The main software that lets the user to interface with the computer machine.
• Video Card - translate data into usable image for the monitor to display. Some use a separate graphic processing unit for more powerful applications and needs
• Sound Card - used to process audio data, recording and playing sound to digital information and back.

PC Connections - the computer connects to the outside world through input/output devices, ports, and networking.

I/O Devices - Monitor, Keyboard, Mouse, Removable Storage
Ports - USB, Firewire
Networking - Modem, LAN, Cable Modem, DSL

Powering Up the PC - the following sequence

1. Turn power ”on”.
2. BIOS doing POST(power-on self test)

• Determines video card
• Verifies RAM, check keyboard, mouse, checks all connections for errors 
• Displays details of the system
• Initiates boot sequence (bootstrap loader) launching the operating system

   3. Boot (bootstrap loader)loads the OS into memory to allow operation

Once loaded, the operating system handles the tasks that controls hardware and software so that the users will be able to interface with the computer.

Abridged from Howstuffworks.com How PCs Work