This is the first article in a series on how personal computers work. For this article, I will start with the basics including the internal and external components that are the building blocks of a computer. I will provide a base definition for each component and for future articles, I will expand on each component by providing detail on how that component functions.

CPU (Central Processing Unit)

The CPU is the brain of the computer. On a personal computer, the CPU is commonly referred to as the microprocessor.

Memory (ROM – Read Only Memory)

The ready only memory (ROM) in a computer is memory that can only be “read” from – that is programs cannot use the memory to write information.

Memory (RAM – Random Access Memory)

The memory (RAM) in a computer is the area where programs and documents are loaded while the computer is in use. The memory is a temporary holding area – once the machine is shut-off, everything is cleared from the RAM.

Motherboard

The motherboard is a circuit board in the computer used to connect the internal components within the computer.

Controllers / Cards

There are controllers for the hard drive along with cards to support video, sound and networking that are connected to the motherboard.

Hard Disk

A hard disk is a permanently enclosed storage device, which is used for the storage of the operating system, user files and programs on a computer. The hard disk is mounted either inside the computer or within a case for external drives.

USB Port (Universal Serial Bus)

The USB port is used to connect external devices, such as keyboards and mice, to the computer.

Keyboard

A keyboard is a peripheral that is used to input data, such as text and numbers, into a computer. The standard keyboard is based after the standard QWERTY layout first used in typewriters though specialized keyboards are becoming more popular.

Monitor

A monitor is used to display the programs and data on a personal computer. The first monitors available where CRT (cathode ray tube) based monitors and where available in an ugly green or orange. Newer monitors are LCD (liquid crystal display) based and have full color capabilities.

Mouse

A mouse is used to navigate the software and operating system, input data and control the computer. Mice come in many different technologies included laser, infrared and the traditional ball based mouse.

Printer

The printer is an output device that allows data, including text and pictures, to be printed from a computer. A printer is usually either an inkjet or a laser and this refers to the type of substance and technology that is used to create the printout.