EVA principle: explanation of input, processing, output

When it comes to electronic data processing, there is often talk of the EVA principle - input, processing, output. But what exactly is behind it? You can find out in this practical tip.

The EVA principle - simply explained

The basic structure of every computer is the EVA principle. EVA is a simple abbreviation and stands for input, processing and output: data is entered first, then processed and finally output. Different hardware components are used for each of these steps.

1. The entry at EVA

In the first step of the EVA principle, the data is entered.

• The input takes place via so-called input devices. These include, for example, a mouse, trackpad, keyboard, scanner, webcam, joystick or a microphone.
• Example: Type a document, enter letters. These letters are the data.

2. The processing

After you have entered the data, it will be calculated by the computer.

• The processing is done by processor, RAM, graphics card, etc. The processor has a control and arithmetic unit. Together with the main memory, it forms the central processing unit. The central unit also accesses the hard disk during processing.
• Example: If you type in a text, the processor sees the letters and processes this information: it is a letter, it is at the top of the page, it has the color black, etc.

3. The output with the EVA principle

After the central unit has carried out all the calculations, the data are output for the user.

• Certain hardware is also assigned to the output devices. The main output device is the monitor. Hardware such as printers and speakers are also output devices.
• Example: If you type in a letter, the input is processed and the letter appears on the monitor. It is output in the form in which the processor processed it: size, position on the page, color, etc.

The abbreviation EDV looks very similar at first glance, but has nothing to do with EVA. In our next article we will explain exactly what is behind the term EDP.