extended memory - Computer Definition
The name given to memory (RAM) in an Intel PC above 1MB (one megabyte). Starting with the Intel 286, extended memory was used directly by Windows and OS/2 as well as DOS applications that ran with DOS extenders. It was also used under DOS for RAM disks and disk caches. Contrast with "expanded memory" (EMS), which was specialized memory above 1MB. Today, most people never heard of extended or expanded memory, because the 1MB barrier was broken long ago, and thousands of megabytes (MBs) of memory are commonly used. See EMS, XMS and DOS extender.