Compatibility mode - Definition and Overview

A mode in which the computer's operating system emulates an older processor and/or hardware platform to allow obsolete software to remain compatible with the computer's newer hardware. This is different from a full-fledged emulator in that while an emulator typically creates a virtual hardware architecture on the host system, a compatibility mode simply translates the older system calls into calls that the host system can understand. Examples include Classic Mode in Mac OS X and Windows XP's compatibility mode.