A computer uses several types of memory units to store, process, and retrieve data, each with a specific role, speed, and capacity.

🔹 1. ROM (Read Only Memory)

• Non-volatile memory: retains data even when the power is off.

• Stores permanent information like system firmware (e.g., BIOS).

• Defined by the manufacturer, cannot be changed by the user.

• Not used for storing personal data or programs.

🔹 2. RAM (Random Access Memory)

• Volatile memory: data is lost when the computer is turned off.

• Stores:

  • Currently running programs,

  • Temporary data.

• Allows direct access to any memory cell by address.

More RAM = Better multitasking and performance.

🔹 3. Cache Memory

• Located between the CPU and RAM.

• Used to speed up data access for the processor.

• Extremely fast but with very limited size.

• Invisible to the operating system.

• Acts as a high-speed buffer for frequently accessed data or instructions.

Often integrated into the CPU in levels (L1, L2, L3).

📌 Summary Table: