The Three-Stage Computing Process

While they may look and act differently, all computers and computing devices allow three key functions to happen: input, processing and output of information.

Input

In order for a computer to do something, it needs to have input. Input is any information given to a computer. Common input devices for personal computers might include the mouse and the keyboard. Any device that provides information to your computer can be considered an input device.

Processing

The processing done by a computer takes place using a special piece of hardware called the Central Processing Unit or CPU, which takes information from input devices and performs tasks.  The outcome of those tasks is then displayed using output devices.

Output

Output refers to the information once it’s been processed by the CPU. Any device that displays information from the computer can be considered an output device. Common output devices include the monitor or screen, speakers, and printer.

The CPU, input devices and output devices work together to form the computing process, which consists of input, processing, and output. Input devices take real-world information and convert it to digital information, which is sent to the CPU, which processes that information, and then sends digital information to output devices, which present that information in a way that the user understands.

Combination Input/Output Devices

Some devices act as both input and output devices. For example, touchscreens are input devices because the user gives information to the computer in the form of tapping and swiping.  However, they are also output devices because they display information back to the user.

How Computers Process Information

As soon as information goes into the computer using an input device, it is converted to a digital, binary format represented as 0s and 1s. It stays in that digital format until it gets presented back to the user with an output device.