What is virtual memory?

• A. When the RAM is full, some secondary storage is allocated as extra space for data
• B. It increases RAM capacity physically
• C. It is non-volatile and stores OS
• D. It is used to store BIOS

Answer: (A)

Virtual memory is a memory management technique that lets a computer use disk space as an extension of RAM. When what’s running needs more space than physical RAM can hold, the operating system moves less-used memory pages out to a reserved area on secondary storage (a page file or swap space) and brings them back when needed. This creates the illusion of a larger, continuous address space, enabling multitasking and the execution of larger programs even with limited RAM. It doesn’t physically increase RAM; it swaps data between memory and disk, which is much slower than RAM access. The system uses page tables and a memory management unit to translate virtual addresses to physical frames, coordinating which pages are in memory and which are on disk. The idea is best described by using secondary storage as extra room for data when RAM is full.