Operating systems use __________ to provide the illusion of a large memory.

Operating systems use __________ to provide the illusion of a large memory.

• A. Physical memory
• B. RAM
• C. Virtual memory
• D. Permanent memory

Answer: (C)

Virtual memory is the technique that allows an operating system to present each process as if it has access to a much larger memory space than is physically installed. It does this by mapping the process’s virtual addresses to actual physical RAM through mechanisms like paging and a page table (often with a Translation Lookaside Buffer for speed). When a program needs data not currently in RAM, the system fetches the data from disk into RAM and may swap out other data to disk. This demand-paging process makes the active memory feel large and contiguous, while the OS enforces isolation and protection between processes. Physical memory is the actual RAM, RAM is the hardware, and permanent memory refers to nonvolatile storage elsewhere; they don’t provide the per-process illusion the way virtual memory does.

Virtual memory is the technique that allows an operating system to present each process as if it has access to a much larger memory space than is physically installed. It does this by mapping the process’s virtual addresses to actual physical RAM through mechanisms like paging and a page table (often with a Translation Lookaside Buffer for speed). When a program needs data not currently in RAM, the system fetches the data from disk into RAM and may swap out other data to disk. This demand-paging process makes the active memory feel large and contiguous, while the OS enforces isolation and protection between processes. Physical memory is the actual RAM, RAM is the hardware, and permanent memory refers to nonvolatile storage elsewhere; they don’t provide the per-process illusion the way virtual memory does.