"DOS-Compatible" refers to software or hardware that can operate with the Disk Operating System (DOS), a widely used operating system in the early days of personal computing. This compatibility allows programs designed for DOS to run on various systems without modification, ensuring users can access a range of applications and games from that era. Many modern operating systems, such as Windows, include a compatibility mode that allows users to run DOS applications. This feature helps preserve the functionality of older software, enabling users to enjoy classic programs while using contemporary technology.