Virtual memory is the memory management technique which is a recent trend of technology used in computers. Computers run software.This software will need computer memory to run and do what in needs .
Most computers in use today can do more than one thing at a time, they run more than one application. This is known as multiprocessing.
in this case,all the programs or applications that are running on the computer at a time share its resources.a computer does not have more processors or main memory just because more programs run on.
Virtual memory is the idea that the application sees a block of memory of a given size. The application can use this memory as it sees fit.