Understanding Computer Hardware

A computer is a system of cooperating parts. Understanding what each part does removes the mystery — and helps you troubleshoot, buy wisely and answer exam questions.

Key Concepts

• CPU: executes instructions — the 'brain'; speed measured in GHz, with multiple cores working in parallel
• RAM: fast temporary workspace; more RAM lets you run more programs smoothly; contents vanish at power-off
• Storage: HDD (cheaper, slower, mechanical) vs SSD (faster, silent, shock-resistant) hold data permanently
• Input devices (keyboard, mouse, scanner, microphone) vs output devices (monitor, printer, speakers)
• Motherboard connects everything; the power supply feeds it; ports (USB, HDMI) attach peripherals

Try It Yourself

Open your computer's system information (or a phone spec sheet) and identify the CPU model, RAM size and storage type. Write down what each number means for daily use.