This kind of memory is an area on a hard drive known as a paging file. Windows uses it as if it were physical memory. What is this?

The Windows operating system will use virtual memory, which is a paging file on a hard disk, as if it were RAM. When necessary, data that would typically stored in RAM is transferred into and out of the virtual RAM. The system can function as if it had more RAM than it actually does, which is advantageous. Because virtual RAM is stored on the hard drive, it has the disadvantage of being slower to access than physical RAM. A computer virtualization software called VirtualBox enables you to run multiple operating systems on a single PC with each thinking it is controlling the hardware. A small outline DIMM (SODIMM) is RAM for laptops. Error correction code (ECC), which is primarily utilized in servers, detects and fixes memory errors.