What type of memory is non-volatile and retains data without power?

• A. RAM (Random Access Memory)
• B. ROM (Read-Only Memory)
• C. Flash memory
• D. Cache memory

Answer: (B)

The correct answer is ROM (Read-Only Memory) because it is specifically designed to retain data even when the power is turned off. This non-volatile memory is typically used to store firmware or software that is not expected to change frequently, allowing it to maintain its contents without the need for continuous power.

ROM ensures that critical program instructions required to boot up a computer or other devices are easily accessible after a power cycle, making it essential for system reliability. Unlike RAM, which is volatile and loses its data as soon as power is lost, ROM preserves its data indefinitely under such conditions.

Flash memory is indeed non-volatile, but it is often used for more versatile storage applications and can be rewritten, which differentiates it from the traditional functions of ROM. Cache memory, while it plays a crucial role in speeding up processes by storing frequently accessed data, is also volatile and does not retain data without power. Thus, ROM stands out as the quintessential example of non-volatile memory that maintains its contents in the absence of power.