What is virtual memory when refering to a computer?
Modern computer operating systems use memory in segments usually called “blocks.” Because the computer can’t really operate on all the blocks at the same time, the operating system can swap blocks it is not using right now out onto a hard-disk drive (or other local storage). This allows it to run as if it had much more RAM (random access memory) than it does by addressing many more blocks than will fit in main memory (RAM). The memory manager just recalls from the disk whichever blocks the programs running need at the time they need them and swaps others not currently in use out if necessary to make room in RAM. Using disk storage in this way to allow the computer to work with and address more information than will fit in system RAM is called virtual memory.
