A computer is the modernity's capable device and the mark of technology brought to the masses. It is made of complex and intricate structures but it is very easy to use. The plainest definition of a computer is that it represents a gadget that receives input, processes it and then produces output. The mechanism is simple in concept but has immense potential in what concerns the various results that come as output. The working principle is rendered through the equation "the input comes in and produces output". Therefore, to understand the technological processes that occur inside the computer, one has to know about the relationship input-output (I / O), notions of processing and storage.

The first concept-I / O- lies at the basis of the activity of a computer. A computer is made of components that are divided into two classes according to their function. These two classes are input parts and output ones. By means of input devices that are connected to the computer, the information enters the system. The keyboard, the mouse, scanners and digital cameras send information to the computer and are examples of input components. Once the computer receives the information, it sends it to output devices that produce different results. Therefore, the image on the screen, the sound from the speaker-boxes, the pages printed are illustrations of the announcement output. The monitor, the speakers, the printer are considered output devices.

The modem is a device that handles both input and output because it receives but also sends information. The computer's storage system is another example of both input-output function component. The information sent to the computer is processed before it is sent to the output devices. Without the processing stage, the information would not be relevant anymore and the computer would be like a tube. The processor is responsible for the activity of transforming the input data in output. The processor operates on the basis of some instructions structured in the form of the software.

The last part in the computer equation is the storage, which represents the "space" where the processor performs its activity. Computer storage is of two kinds: temporary and long-term.

Temporary storage, also called RAM, supplies the computer with memory, where programs run and the information is stored while it is worked on. When the microprocessor is not directly working on the information, long-term storage allows the computer to save data on storage media. Hard drives, media cards, flash drives, optical discs, CDs and DVDs are such storage media. They save information which can be recalled for later use.

Making an analogy between the computer and the human body, RAM (random access memory) is equivalent to an individual's memory. We temporarily store information in our head. To make sure we do not forget it, we write it down. The pad of paper used to write the received information is equivalent to long-term storage.