How does the computer’s brain know what to do next?

It uses a simple process over and over:

  1. Fetch the instruction

  2. Decode what it means

  3. Run the action

  4. Move on to the next one

This is called the fetch-decode-run cycle.

Let’s break it down like a story.

 

📖 Step 1: “Go Get the Next Step”

Imagine your brain is standing in front of a recipe book.

First, it reads the first line:

“Mix sugar and flour”

That’s the fetch step.

 

🧾 Step 2: “What Does This Mean?”

Now it looks at the words:

“Mix sugar and flour”
Okay — I understand what to do.

That’s decode.

The computer’s brain looks at the 1s and 0s and decides what that instruction wants.

 

🛠️ Step 3: “Let’s Do It!”

Now the brain carries out the job:

  • Mixes

  • Adds

  • Shows

  • Saves
    Whatever it says.

That’s the run step.

Then… it moves to the next instruction, and starts over.

 

♻️ It Does This Over and Over — Really Fast

Most programs have millions of steps.

But the brain doesn’t care.
It keeps going:
Fetch → Decode → Run → Repeat

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