What is the main idea of this?

Hello everyone.





I have to extract the main idea of the following text, but I'm utterly confused. Take a look:





Computers are electronic machines for processing data. Data are pieces or items of information that have been proper prepared so that the machine can work with them. Processing means handling or manipulating the material that has been presented to the machine in such ways as performing calculations, classifying information or making comparisons. A computer is made of millions of electronic devices that can store the date or switch them through complex circuits with differentes functions at incredible speeds.





The collection of devices that constitute a computer are technically known as a computer system. This system consists of functional components, or parts, for input, storage, control, processing, and output. All general-purpose computer systems has these components, but their physical characteristics may vary





The main storage, control and processing components constitute the heart of the computer system. The central processing unit (CPU) has been designed by the manufacturer to control and carry out basic instructions to that particular computer. It is here that the data processing is done. The C.P.U has two components, called the control and arithmetic units. Input and output are handled by machines that are called I/O devices.





What confuses me is that I do not see a real main idea, except for the components of a computer.


So, what do you think is the main idea? (I have to underline it)





Thanks in advance|||To me, the one sentence or phrase that comes closest to a main idea is this one: "A computer is made of millions of electronic devices that can store the date or switch them through complex circuits"