operating system
compound.compound. the main software that controls a computer or phone. It manages all the other programs and helps the hardware work with the software.
compound. the primary software that manages computer hardware, software resources, and provides common services for computer programs.
I need to update my operating system to the latest version.
Most people choose their smartphone based on whether they prefer the Android or iOS operating system.
The stability of an operating system is critical for server environments where even a few minutes of downtime can result in significant financial losses.
A compound of the present participle of the verb operate and the noun system. The term emerged in the 1950s to describe the supervisory software developed for mainframe computers such as the IBM 704.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Often abbreviated as 'OS' in technical and informal contexts.
Last updated July 22, 2026