The CPU or Central Processing Unit (Central Processing Unit in Spanish) is the central part of every computer since it is the one that fulfills the task of processing all functions as well as storing information. It is an electronic circuit that has always existed in computers regardless of its model and that is why it is considered one of the basic elements of any computer.
It should be a general purpose element, to which the software dictates what to do. There are specific processors to carry out a specific task, which although some authors consider as CPUs, others do not. My position on this is clear: a CPU must be, I insist, general purpose.
The first designs of machines that we can consider as precedents of today's computers did not have a CPU as such. The first generation of computers did not have a single element that acted as a CPU, but that function was distributed among various elements of the hardware.
To have the first CPU put together in a single piece, specifically on a chip, we have to go back to the beginnings of silicon technology and, more specifically, to the Intel 4004 of 1970.
The new technology not only made it possible to give these machines more power while occupying a smaller volume, but also made them cheaper and, consequently, facilitated their adoption by a more massive public.
Technological advances in CPUs made it easier for them to notably increase the execution speed of programs, and for us to find several CPUs integrated on a single chip.
The latter is what is called multicore architecture, and it is what leads us to say that this or that chip has a "dual core" or "quad core", among other possibilities.
But computers are not the only devices that have CPUs; Smartphones, tablets and even televisions have chips that perform this function and that give them “intelligence”, providing the “smart” part of the word, as in a smartphone or smart TV.
The CPU must communicate with the rest of the components of the computer or the device in which it is mounted, something that is done through what is called a bus.
The different buses communicate the CPU with each of the other components of the computer system such as input and output (I / O) ports, expansion slots (which leads the CPU to communicate with PCI cards), or the graphics card.
Although Intel was the manufacturer that started the era of silicon chips, and modern CPUs, it does not remain exclusive in this area.
There are manufacturers that offer alternatives, whether or not they are compatible with the chips of this company. For example, AMD (Advanced Micro Devices) offers a line of Intel-compatible CPUs.
On the other hand, Qualcomm offers a line of CPUs that work in a totally different way than Intel or AMD.
The architecture of the microprocessor is what defines how the CPU works.
This implies how the instructions work and what are the limitations that programmers have, and how they can work. Each CPU has its own set of instructions for its architecture.
There are currently two architectures that cover almost the entire market: x86 (and its 64-bit extension, x86-64), and ARM. The first for desktop computers, and the second for mobile devices of all kinds.