Why CPU is Brain of Computer?

By Puja Chatterjee on December 15, 2022

Your computer’s CPU i.e., the Central processing Unit is comparable to a human brain. Just like our brain processes every piece of information that it receives from other parts of our body, the CPU is responsible for processing each operation that we perform on/using our computers.

Simple mathematical operations take place whenever any action is performed by your computer.

Similar to how your brain sends signals to make any organ or part in your body work, your CPU also sends signals according to these mathematical calculations, to control every internal component and its actions.

5 Reasons Why CPU is Brain of Computer

Why CPU is Brain of Computer

A human brain is made up of thousands of neurons, similar to your CPU’s millions of transistors. Neurons as well as transistors are used for sending and receiving electrical signals.

A CPU is called the brain of a computer, since it acts similar to a human brain. Listed below are some reasons why the CPU is the brain of a computer.

1. Connector Between All Parts

A human brain acts as a connector between all body parts and organs as all these parts have to communicate their message to the brain first, which in turn relays these messages to specific organs or parts.

No body part can send signals to each other without your brain’s presence.

Similarly, your computer’s CPU is used by all other internal components as a mediator.

For example, if your GPU needs some information from main memory regarding a game, it will send a message to your CPU.

After receiving this information your CPU sends a signal to your main memory to send required data.

It then receives this data and passes it on to your GPU (Graphics Processing Unit). This is how every internal component of your system operates.

2. Information Processing

A human brain starts processing information that is transmitted to it from sensory organs. This data is first processed to a certain extent to decide if it is urgent and requires immediate attention from other organs.

Then this information is stored in memory from where it can be accessed later on for better analysis.

Your CPU processes instructions through four functions namely, Fetch, Decode, Execute and Store.

The first step of this process is Fetch, which simply means receiving one set of instructions or multiple tasks.

These instructions are sent to your CPU from your RAM (Random Access Memory) and are available in binary code.

Binary code is made up of binary numbers 0 and 1, and is your computer’s method of communicating with its internal components.

Read Also:  What is CPU Clock Speed? (Explained)

A CPU never processes an entire piece of code as a whole. Every instruction your CPU processes is a small fraction of this code.

This happens because your RAM stores all this information in small pieces as separate blocks which are stored randomly in this memory component.

Your CPU does not receive these instructions randomly, as even this action needs CPU to call a set of instructions from a particular address in your RAM.

In order to access every instruction in a proper order, your CPU needs to remember all addresses in your RAM in order of how they need to be accessed.

Your CPU employs a counting mechanism, which assists your CPU by keeping record of addresses in your RAM, from which these tasks are being sent.

Through this program counter, your CPU knows that if the current instruction that it is processing is at 5th position according to this counter, next set of instructions will be sent to your CPU from an address stored in 6th position of this counter.

All tasks are first stored in an instruction register, allowing your CPU’s program counter to move to the next position and begin accessing the next set of instructions.

After your CPU has accessed a piece of code and stored it in an instruction register, it gets decoded.

Your CPU’s instruction register not only stores this task but also decodes it to signals. It then sends these signals to different components in your CPU for further processing.

These instructions are processed by your CPU’s ALU (Arithmetic Logic Unit) and then sent to memory to get stored or to an output device, for instance to your monitor, if it has to be displayed, or your speaker, if it has to be played as audio.

This proper organized storage and accessing of data is possible only because your CPU is in-charge of all activities.

3. Multitasking

Multitasking means an attempt to do more than one thing simultaneously. A human brain cannot actually multitask, since it is difficult for your brain to focus on two things at the same time.

However, your brain creates an illusion that it is actually multitasking, by processing two different tasks bit by bit.

It keeps changing from one process of one task to one process of another task. This processing and switching is done within a few milliseconds which is why it appears as multitasking.

Your computer too, is able to handle multiple tasks in a similar manner.

Your CPU acts like a human brain and allows you to open multiple tabs in a browser, use multimedia applications, and multiple programs at once.

Read Also:  What is Hyper Threading? Works, Uses, Example & More

Regardless of your CPU’s processing speed or power, a single CPU cannot perform true multitasking.

For instance, you are operating a browser with 5 tabs open and Microsoft PowerPoint application to create a presentation for work/school.

Even if you have both applications open and running on two halves of your screen you cannot look at both of them at once. You will have to take a glance at one and then move your eyes on to the other one.

Similarly, just because you are forcing two applications to share your CPU’s and monitor’s resources, it cannot process information related to both at once.

Your CPU has collected information about each task separately, including all five tabs of your browser as well as the presentation you are working on.

Even if they are associated with the same topic, according to your CPU, each one is a different task.

Your computer’s processor cannot consider even multiple tabs open in one browser as a single task, regardless of whether or not they are associated by similar topics or content.

Once this information is stored in your RAM, your CPU is ready to perform any big or small task, belonging to any of these processes.

As soon as you start issuing instructions to your CPU through your actions, your CPU starts accessing required processes from RAM and starts executing them.

A single CPU core can be divided into two virtual processors known as threads. Each thread can operate as a single, independent processor. True multitasking by one CPU core is only possible in this scenario.

Multicore CPUs also allow parallel processing or multitasking, as each core functions independently as a single CPU.

When they are further divided into threads, your CPU’s ability to perform multiple tasks simultaneously increases significantly.

4. Information or Memory Storage

A human brain not only controls all actions performed by a human body, but also acts as a memory location. All your memories get stored in your brain, be it temporary or permanent.

When your brain requires any additional information to process any data, it accesses it from your memory, since it knows where necessary information is stored.

A CPU is known as a computer’s brain because similar to a human brain, it stores and accesses information from memory.

Your CPU uses RAM and main memory for storing information, which is accessed according to your system’s requirements.

A CPU not only uses these memory devices for storing information but also stores information in itself.

A CPU has numerous registers, which are used for storing information even if it is for a short duration.

The duration for which your CPU stores information in its registers is very brief, as CPU keeps accessing new information several times in every second.

Read Also:  What is Turbo Boost Technology? Pros, Cons & More

Old information is no longer useful to your CPU, which is why after a task is executed, its details are immediately removed from your CPU’s register.

This is done to make space for incoming tasks that need to be stored in your CPU to be decoded and processed.

Your computer’s central processing unit is not a permanent storage device; therefore, it will not store information for a long-term.

However, it is your CPU’s responsibility to decide which piece of information gets stored at which location.

Once a set of instructions is processed, data either gets converted to signals and processed further or gets deleted as it is no longer useful to your system for carrying out any other tasks.

5. Purpose

Your CPU’s purpose is to execute instructions. These instructions include simple calculations like addition, subtraction and multiplication.

Instructions are created or triggered by your actions while using a computer.

If you use your mouse to click on a link in a web browser, your CPU needs to perform this click and then access information being sent out and received through your browser.

It is done to ensure all data sent and received is safe. It then has to access this data and convert it into a form that is readable.

Your system’s memory devices’ purpose is to store data and retrieve it according to your CPU’s commands.

Your brain is fairly similar to your CPU as it uses all information gathered through your senses, processes it and utilizes it to ensure your body remains safe and healthy.

Your brain uses your entire body to access new information regarding its surroundings or other details making it easier to determine how to behave or respond in certain situations.


Now that you have read about how your CPU’s actions are similar to your brain, you know why the CPU is the brain of a computer.

You do not need to understand intricate details or gain in-depth knowledge of how your brain or a computer’s CPU functions in order to understand these similarities.