What is a CPU?

Computers have been around for decades and have worked their way into almost every home, school, and business. Despite the prevalence of computer equipment, many people are still confused by some of the technical language and jargon that comes with the territory.

Computers consist of a variety of components, each of which performs an individual function to ensure the system works as a whole. One of these components is the CPU, which is an incredibly important part of any operating system.

Here we will outline exactly what a CPU is, what it does, and some examples of this vital piece of the computing puzzle. 

What does CPU stand for? 

Like many computing components, CPU is an acronym. CPU stands for Central Processing Unit but can also reference a main processor or any processor. 

What is a CPU? 

The CPU is essentially the computer’s brain and carries out instructions from the system software. It performs calculations, logic checks, controls, and input/output (I/O) operations that are communicated to it by the software. It is an internal component not usually exposed outside a computer device’s casing.

What is the CPU made from? 

The CPU consists of a silicon chip that is set into a special socket on the computer’s motherboard. These components contain billions of tiny transistors on the chip, enabling it to carry out the calculations and operations outlined above. As they turn on and off, they convey 1s and 0s to translate any electronic input into an operation. 

The CPU will largely determine the speed of the computer and its response to inputs. Over the years, the transistors on the chip have become smaller, resulting in increased speed. There is even an observed law that states that the number of transistors in an integrated circuit doubles every two years, known as Moore’s Law. 

However, not every CPU is constructed in the same way, as some CPUs are part of a System on Chip integration. 

What is System on Chip (SoC)?

In some devices, such as mobile and tablet computers, the CPU is embedded into a chip alongside other components. This is known as a System on Chip (SoC) approach, which can package the CPU alongside the GPU and memory

What is the difference between a CPU and a GPU?

We just mentioned a GPU, which may also have left you scratching your head. GPU stands for Graphics Processing Unit and is similar to the CPU but specifically designed to process graphics-related tasks. This can be things like displaying visuals on a screen, rendering 3D images, and more. In addition, the CPU and GPU will generally work together to offer even faster computer processing speeds. 

As well as a separate and dedicated GPU component, there is also the option for integrated graphics. Integrated graphics means that the GPU and CPU are built into the same chip, which can be efficient for some users but less effective for heavy graphics-based tasks such as video editing, gaming, and design. 

What does a CPU do? 

We have touched on the basic function of a CPU briefly already, but here we will break down its function in more detail. 

The CPU will generally receive, interpret and carry out commands. The commands are received from the RAM (Random Access Memory), and the CPU then interprets this command.

This command may need to be resolved through some simple mathematics or basic functions. The language of computer systems is numbers, so the CPU can be considered an extremely rapid calculator. This command may launch a piece of software, display an image on the screen or carry out a calculation on a spreadsheet. These steps are commonly referred to as fetch, decode and execute. 

The CPU can also assign tasks to other, more specialized components of the computer system. If you need to display a visual from a video game, for example, the CPU will assign this task to the GPU. 

CPU cores

Early CPUs made use of a single processing core, although modern CPUs made use of multiple cores. Having more than one core allows the CPU to carry out many actions at once, increasing the system’s speed and response times. 

Clock Speed

When looking at CPUs, you may encounter a clock speed specification. This number is presented in the unit of gigahertz (GHz). Essentially, this number determines how many instructions a CPU can carry out every second. Generally, a higher clock speed will denote a faster processor. 

History of CPUs

So now you have a basic idea of what a CPU is and what it is, but what is the component’s origin? 

The term has been used since 1955, with the first devices that could be referred to as CPUs emerging in the 1940s. 

However, CPUs, as we know them today, first came to light through the Intel 4004. This was the world’s first microprocessor with a CPU on a single chip. It was released in March 1971 and was incredibly important for the drastic advancement of computer systems over the next few decades. 


All you need to remember is that a CPU is the component of the computer that fetches inputs, decodes the instructions, and then executes the command. These commands can be distributed to more specialized hardware, such as the GPU. Many types of CPUs have different speeds, constructions, and sizes. They are used in various devices, from mobile phones to computers. 

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