What Is a CPU? Central Processing Unit Defined

What Is a CPU? Central Processing Unit Defined

CPU stands for Central Processing Unit. It is also sometimes called a microprocessor or simply “the processor.”

The CPU is the brain of a computer. It does all the calculations and processes the data in a computer. CPUs are found in all desktop, laptop, and tablet computers, even in smartphones.

How Does The CPU Work?

So, you want to know how your CPU works? Well, the CPU is where instructions are executed.

When the computer starts up, an instruction is fetched from the RAM by the control unit and put into the instruction register (IR).

The IR temporarily stores that instruction while decoded and then executed by the arithmetic logic unit (ALU).

The ALU takes information as input from several storage locations called registers.

Registers store data and addresses until the CPU or other computer parts need them.

Some common registers are:

  • Instruction Register (IR): Stores the current instruction being executed.
  • Program Counter (PC): Keeps track of which memory location contains the next instruction to be fetched for execution.
  • Accumulator: Used for storing intermediate results when performing arithmetic operations like addition or subtraction.

There’s also cache memory inside every modern processor that speeds up access to frequently used data in RAM by storing it locally on special high-speed memory chips located close to its core components.

The CPU can communicate with other parts of your computer using something called a bus—a communication pathway between two or more devices inside your machine that lets them talk back and forth with each other so they can share resources.

Parts of a CPU

The CPU is divided into 3 parts: The control unit, the arithmetic logic unit, and the memory unit.

  • Control Unit: This part of the CPU makes sure that all processes happen in a sequence. It does this by making sure that the computer executes everything in order. It also makes sure that each part of your computer has access to each other part when needed.
  • Arithmetic Logic Unit: The ALU does all the math for you. Whenever you use numbers on your computer, it’s doing some kind of math with them (even if you’re talking about numbers). So whenever you use numbers on your computer, it goes through the ALU first. The actual name “Arithmetic Logic Unit” comes from how it can do both arithmetics (adding, subtracting, etc.) and logic (using true/false statements). The more advanced your ALU is, the more quickly it can add two big numbers together or find out if two big numbers are equal.
  • Memory Unit: The memory unit is where all of your programs go once running. When you open a program on your computer (like Microsoft Word), it gets loaded into this part of your CPU so that it runs as quickly as possible. Programs stay here until they’re finished running or until another program needs that space for itself again.

Difference Between CPU and GPU

You may have heard about the difference between CPUs and GPUs—they’re the two primary technologies that power computers.

In this article, you’ll learn what a CPU is and what it does, how it’s different from a GPU, and how they work together to create your digital life.

A CPU is the main processing unit of a computer system.

It interprets software instructions, performs basic mathematical operations like addition and subtraction, controls input/output devices such as keyboards and printers, moves data from one place in memory to another, and stores intermediate results.

CPUs are generally expensive because manufacturing them accurately requires a lot of time and money: transistors must be made out of silicon or germanium crystals whose atoms must all lie flat on top of each other without any defects; if there aren’t enough atoms per square nanometer then performance suffers dramatically!

The CPU is responsible for executing programs in order (i.e., taking input from memory location A then putting output back into B after adding 1).

All computing power comes down to these two tasks: fetching instructions from memory locations X+1 before executing them (which requires reading data) and writing new outputs back into Y+2 after some operation on X+1 (which requires writing more data).

How Does The CPU Help in Gaming?

A CPU is not that critical for Gaming, but it is an essential companion to a GPU.

Your system won’t even start and start the game without the CPU.

A high-end GPU will not work if you don’t have a high-end CPU to go with it.

A high-end GPU needs a powerful CPU to do all the processing for it so that the GPU can focus on graphics rendering.

If you want excellent performance from your system, having a powerful CPU is necessary.

Suppose you want to build an entry-level gaming PC or something that can only run older games.

In that case, the CPU doesn’t matter much, and an Intel Core i3 or AMD Ryzen 3 should be enough for this build.


The CPU is an essential part of any computer. It is the computer’s brain that does the work and makes decisions.

On the other hand, the processor is the heart of a computer that determines how fast it can perform.

CPU is also used in artificial intelligence applications.

Further Reading