Software used to control the computer and develop and run applications. It includes programs such as operating systems, database managers, compilers, Web servers, router operating systems and control programs for other network devices. Contrast with application program.The following diagram shows the flow between system software and application software residing in memory in a multiuser computer. The operating system (OS), TP monitor, database manager and interpreter are considered system software. The applications and interactive DBMS query and edit would be considered application software.