One way to look at the Computer is as “A machine that performs data processing.” When you look at the computer from this point of view, you need to look at every device associated with the computer from this perspective. Before delving deep into the topic of Data processing, let’s first understand what is meant by the term ‘Data Processing’. The word processing means ‘A series of actions, changes, or functions bringing about a result’. Data processing means that you act upon the data to turn into other meaningful data. So there is something before and after the act of processing. That something before processing is often referred as input. The something after processing is called output. In the case of data processing, both input and output is the data. The input and output data may or may not be similar. If they are similar, the data may not have been acted upon. An intuitive example is when you use a clean tube to transfer water. Water(input) is passed through a tube from one end of the tube and you get the (same)water at the other end(output). But in most cases, we use the computer or any device to get a different output from the input we fed in. In case of computer, we often call the output data as (meaningful) information.
Let’s take some real word examples to see what processing means. Take a juicer. What you feed in the juicer are the peeled fruits and you get as output pulp extracted from the juice. You can also see a change in state. The input was in solid state and the output is in liquid state. Thus a juicer is also a processing machine. It processed upon the fruits and returned the juice of the fruits as output.
A computer is a data processing machine. A computer has many devices attached to it. When you press a key on your keyboard, it generates electric signals which must be transformed to the pixels on the screen. The computer aids in this transformation to display the key at the right place on the screen. So a set of electric signals (input) is transformed to another set of electric signals(output) to display the pixels in the desired color. We abstracted out many inner details of this processing and presented an overall picture. What happens exactly is there are a number of data processors (any entity capable of data processing) working in a series (or in parallel) that is aiding the transformation. Each data processor does its intended duty to transform the data to another form of data. When all these data processor are arranged in a proper manner, we are able to see the character displayed on the screen.
Take any other example from our daily lives, we see the (data) processing. A camera, a mobile phone, a vacuum cleaner, a dish washer, a washing machine. All of these take something as input and give another meaningful or helpful output. All these devices process the data fed into them. The output is in the form that you want.