Know and understand differences between ROM and RAM

1 Types and Components of Computer Systems

ROM (Read‑Only Memory) 🗂️

ROM is the memory that never changes. It holds the firmware – the basic instructions that tell the computer how to start up. Think of it as a recipe book that you can read but never edit. The data in ROM stays there even when the power is turned off, so the computer always knows how to boot.

• Permanent storage – data is retained without power.
• Non‑volatile: survives power loss.
• Used for firmware, BIOS, and system boot instructions.
• Cannot be written to by the CPU during normal operation.

RAM (Random Access Memory) 🧠

RAM is the computer’s short‑term memory. It holds the data and instructions that the CPU is actively using while a program runs. Imagine a whiteboard where you can write, erase, and rewrite information instantly. When you turn off the computer, everything on the whiteboard disappears.

• Volatile storage – data is lost when power is removed.
• Fast read/write speeds for quick access.
• Used for running applications and temporarily storing data.
• Can be written to and erased by the CPU.

Key Differences in a Table 📊

Quick Quiz 🎓

1. Which type of memory keeps its data even after the computer is turned off?
2. What is the main reason RAM is called “random access” memory?
3. Give an everyday analogy for ROM and for RAM.