Which of the following retains the information it's storing when the power to the system is turned off?
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CPU
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ROM
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RAM
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DRAM
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DIMM
To solve this question, the user needs to know the differences between the types of computer memory.
A. CPU (Central Processing Unit) is not a type of memory, it is a processing unit that performs most of the processing inside a computer.
B. ROM (Read-Only Memory) is a type of non-volatile memory that retains its data even when the power is turned off. It is used to store firmware, BIOS, and other permanent system data.
C. RAM (Random Access Memory) is a type of volatile memory that does not retain its data when the power is turned off. It is used to temporarily store data while the computer is running.
D. DRAM (Dynamic Random Access Memory) is a type of volatile memory that requires constant refreshing to retain its data. It is used as the main memory in most computers.
E. DIMM (Dual In-Line Memory Module) is not a type of memory, it is a form factor for RAM modules.
Therefore, the correct answer is B. ROM.
ROM (Read-Only Memory) is non-volatile: it retains its stored data even when power is removed, which is why it's used for firmware/BIOS that must persist across power cycles. RAM and DRAM are volatile memory — their contents are lost the instant power is cut, since they rely on continuously refreshed electrical charge to hold data. A DIMM is just a physical module form factor (commonly holding volatile RAM), not inherently non-volatile. The CPU is a processor, not a storage medium, and holds no persistent data of its own. So ROM is the only option that genuinely retains information without power.