Computer Hardware: Input, Output, Processing and Storage
Inside a Computer System
This KS3 computing lesson explores Computer Hardware: Input, Output, Processing and Storage. Students identify key computer components and explain how input devices, processors, memory, storage and output devices work together in a computer system. It provides a clear introduction to the topic and can be used for classroom teaching, homework or revision.
Lesson duration is: 55 minItems in this lesson
Inside a Computer System
This KS3 computing lesson explores Computer Hardware: Input, Output, Processing and Storage. Students identify key computer components and explain how input devices, processors, memory, storage and output devices work together in a computer system. It provides a clear introduction to the topic and can be used for classroom teaching, homework or revision.
Computer Hardware, KS3 Computing, Computer Science, CPU, RAM, ROM, Motherboard, Secondary Storage, Input Devices, Output Devices, Magnetic Storage, Solid State Drive, Optical Storage, Von Neumann Architecture, MCQs, Open Questions, Polls, Emoji Polls, Exit Tickets
What computer parts do you already know?
Use this to surface prior knowledge. Expect words like keyboard, mouse, screen, CPU, printer, software. Briefly sort answers into hardware and software without correcting every detail yet.
Hardware and software
Hardware is the physical part of a computer
You can see and touch it
Software is the set of programs and instructions
Hardware needs software to tell it what to do
A simple comparison helps here: keyboard, screen and motherboard are hardware; a web browser or game is software.
They work together
A computer system is not just one device. The hardware carries out jobs, but the software gives the instructions. Without hardware, the software cannot run. Without software, the hardware has nothing useful to do.
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Main hardware groups
Input devices send data to the computer
Internal components process and store data
Output devices present results to the user
This slide sets up the lesson structure: first the hardware/software difference, then internal parts, then input and output, then the full system flow.
A simple system flow
Input device → data enters the computer → internal hardware processes or stores it → output device shows the result
Keep the idea general for now. Later slides attach each named component to one part of this flow.
Which statement is correct?
Hardware is physical
Software you can touch
Hardware gives instructions
Software is a keyboard
Checks the hardware/software contrast from slides 2–3. Distractors target common mix-ups between parts and programs.
Complete the computer system idea
A computer system needs both hardware and software. Input devices send data in, internal parts process or store it, and output devices show the result.
Echoes the wording of slides 3–5 and checks the basic system flow.
The CPU
CPU means Central Processing Unit
It carries out instructions from software
It processes data and controls many tasks
It is often called the 'brain' of the computer
Avoid suggesting the CPU works alone; later slides show that it depends on RAM, storage and the motherboard.
RAM
RAM means Random Access Memory
It holds data and programs the CPU is using now
It is temporary memory
When the power is off, RAM is cleared
Students often mix up RAM and storage. Stress 'using now' versus 'kept for later'.
Storage: HDD and SSD
SSD
Solid State Drive
Also keeps files after power is off
No moving parts
Hard Disk Drive
Stores files after power is off
Uses moving parts
HDD
You do not need to go deep into speed unless helpful. The key idea is that both are long-term storage, unlike RAM.
Motherboard and power supply
The motherboard is the main circuit board
It connects the CPU, RAM, storage and other parts
The power supply gives electricity to the computer
Without power, the components cannot work
If useful, mention that the motherboard is like the main connection point inside the computer.
How internal parts work together
Software gives instructions. The CPU processes them, RAM holds what is needed now, storage keeps files for later, the motherboard links the parts, and the power supply keeps the system running.
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Which part holds data the CPU is using now?
Motherboard
Storage
RAM
Power supply
Tests the key contrast between RAM and storage from slides 7–10.
Complete the internal components summary
The CPU carries out instructions. RAM holds data being used now. Storage keeps files for later, and the motherboard connects the parts.
All blanks are load-bearing terms from slides 6–10. Remind students that storage can be HDD or SSD.
How is RAM different from storage?
Expected answer elements: HDD and SSD keep files after power is off, while RAM is temporary and is cleared when power is off. Accept simple comparisons in student language.
Input devices
Input devices send data into the computer
Keyboard enters text and commands
Mouse controls the pointer and selects items
Link back to the system flow: these devices are where information enters the system.
What input devices do
When you type on a keyboard or move a mouse, the device sends signals to the computer. The computer then processes those signals as data or commands.
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Output devices
Output devices present results from the computer
Monitor shows text, images and video
Speakers produce sound
Printer produces a paper copy
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From processing to output
After the internal components process the data, the computer sends the result to an output device. This lets the user see, hear or print the information.
Reinforce that output devices do not do the main processing; they present the result.
Which device is an output device?
Keyboard
Mouse
Monitor
CPU
Checks recognition of input versus output after slides 11–14.
Complete the input and output explanation
A keyboard sends text into the computer, and a mouse sends movement and clicks. After processing, a monitor shows the result, and speakers produce sound.
Uses familiar examples from slides 11–14 and reinforces what goes in versus what comes out.
The full computer cycle
Input → processing → storage → output
A computer receives information, works with it, saves it if needed, and produces a result for the user.
This is the main idea that resolves the lesson: each hardware part has a job in the wider system.
Example: typing a document
Keyboard sends input
CPU processes the instructions
RAM holds the data being used
Storage saves the file
Monitor shows the text
A concrete example helps students connect abstract parts to a familiar task.
One system, many parts
Each hardware component has a different role, but they depend on one another. A computer works well because its input devices, internal components and output devices operate together as one system.
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In typing a document, what saves the file?
RAM
Storage
Monitor
Keyboard
Applies the full system cycle to the example on slides 15–17.
How confident do you feel about what you learned in computing today?
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Glossary 1
hardware - the physical parts of a computer that you can touch
software - programs and instructions that tell the hardware what to do
CPU - the component that processes instructions and data
RAM - temporary memory that stores data and programs in use
storage - the place where files and data are kept for later use
motherboard - the main circuit board that connects computer components
power supply - the component that provides electricity to the computer
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Glossary 2
HDD - a hard disk drive that stores data using moving parts
SSD - a solid state drive that stores data without moving parts
input device - hardware used to send data into a computer
output device - hardware used to present results from a computer
keyboard - an input device used to enter text and commands
mouse - an input device used to control the pointer
monitor - an output device that displays information on a screen
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