What is the key functional difference between RAM (Random Access Memory) and ROM (Read-Only Memory) in a computer system?

The defining functional difference is volatility: RAM is volatile memory, meaning its contents are lost the moment power is removed, which is why it's used for temporary, actively-used data such as running programs and their working data. ROM is non-volatile, retaining its stored data even without power, which is why it's typically used to store firmware or boot instructions that must persist across power cycles. Option A actually reverses RAM's and ROM's typical roles, option B reverses which type is read-only versus writable in normal operation, and option C's claim about exclusive physical locations doesn't reflect how these memory types are actually deployed across different systems.