What do you do when you run out of real random access memory (RAM)? Easy. Pass it off to virtual memory. To do this you need a virtual memory manager (usually a function of the operating system) that maps chunks of data and code to storage areas that aren't RAM. Virtual memory is really a part of your hard disk called a swap file, dedicated as a storage area for bits of data in RAM that aren't being used much. By freeing up RAM, you're virtually increasing the amount of working memory available to you.