Virtual memory is a computer system technique that allows a computer to compensate for its physical memory (RAM) shortage by temporarily transferring data from RAM to a designated section of a hard disk drive or solid-state drive. This section is called a paging file or swap file.
Virtual memory is important because it allows computers to run more programs and store more data than would be possible with physical memory alone. It also helps to improve the performance of computers by reducing the amount of time spent waiting for data to be transferred from the hard disk drive to RAM.