Computer ScienceThe Main Parts of a Computer and Their Jobs
Byte the friendly robot sits at a bright classroom table, pointing happily at a big colorful computer with a keyboard, a screen, and a glowing brain-shaped chip in the middle, while paper cards labeled IN, THINK, and OUT float in the air around them.
- Identify the part of a computer that takes information in.
- Identify the part of a computer that thinks and figures things out.
- Identify the part of a computer that shows the answer.
- Explain in one sentence what each main part of a computer does.
Key terms
- input
- information that goes into the computer, like a key press
- processing
- when the computer thinks and figures out what to do
- output
- the answer the computer shows or plays for you
- processor
- the tiny chip that does the thinking inside a computer
The Three Jobs Every Computer Does
No matter how big or small a computer is, it always does three jobs in the same order: take information in, think about it, and show the answer out. We call these input, processing, and output. A phone, a laptop, and even a game machine all follow this same IN, THINK, OUT path. Once you know these three jobs, you can look at any computer part and figure out which job it is helping with.
Input and Output Parts
Input parts carry information into the computer. A keyboard sends letters in, a mouse sends clicks in, and a microphone sends sound in. Output parts carry information back out to you. A screen shows pictures and words, and speakers play sound you can hear. A helpful way to tell them apart is to ask which way the information is moving: if it goes toward the computer it is input, and if it comes toward you it is output.
The Processor Does the Thinking
Between input and output sits the processor, a tiny chip deep inside the computer. It takes the information that came in, figures out what to do with it, and decides what to send out. The processor is the only part that actually thinks. The screen does not think; it only shows what the processor already decided. Keeping these jobs separate helps you avoid a common mix-up between showing an answer and figuring one out.
Worked examples
Trace the three jobs when you type a letter and see it appear.
- You press a key on the keyboard, so the keyboard does the input job.
- The processor reads the key press and decides which letter to make, doing the processing job.
- The letter appears on the screen, so the screen does the output job.
Answer: Keyboard is input, the processor is processing, and the screen is output.
Activity
Drag each computer part to the job it does: IN, THINK, or OUT.
Practice
Sort these into input or output: mouse, speakers, microphone, screen.
Tell a friend why the screen is not the part that does the thinking.
Common mistakes to avoid
- The screen is the thinking part.The screen only shows answers; the processor chip is the part that actually figures things out.
- A keyboard shows the computer's answer.A keyboard is an input part that sends information in, not an output part that shows answers.
Check your understanding
You type your name on the keyboard. What job is the keyboard doing?
The screen shows you a picture. What job is the screen doing?
Byte says the processor chip is the THINKING part. A friend says the screen is the thinking part because that is where answers appear. Who is right?
Recap
Every computer does three jobs in order: input takes information in, processing has the processor think about it, and output shows or plays the answer. Keyboards and microphones are input, the processor chip does the thinking, and screens and speakers are output. IN, THINK, OUT happens every single time.
Reflect
Pick a device you use and name one input part and one output part it has.