operating system

American  

[op-uh-rey-ting sis-tuhm] / ˈɒp ə reɪ tɪŋ ˌsɪs təm /

noun

Computers.

1. the collection of software that directs a computer's operations, controlling and scheduling the execution of other programs, and managing storage, input/output, and communication resources. OS

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operating system British  

noun

1. the set of software that controls the overall operation of a computer system, typically by performing such tasks as memory allocation, job scheduling, and input/output control

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operating system Scientific  

/ ŏp′ə-rā′tĭng /

1. Software designed to handle basic elements of computer operation, such as sending instructions to hardware devices like disk drives and computer screens, and allocating system resources such as memory to different software applications being run. Given uniformly designed operating systems that run on many different computers, developers of software do not need to concern themselves with these problems, and are provided with a standard platform for new programs.

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operating system Cultural  

1. The software that allows computer users to run applications with the hardware of a specific system. Microsoft® Windows® or Apple® Computer's OS are examples of operating systems.

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Etymology

Origin of operating system

First recorded in 1960–65

Example Sentences

An Anthropic blog post said weaknesses could be found in “every major operating system and every major web browser when directed by a user to do so.”

From Barron's • Apr. 10, 2026

BlackBerry BB 1.03%increase; green up pointing triangle laid out its fiscal 2027 growth outlook after reporting a fourth-quarter profit, supported by robust revenue from its QNX real-time operating system segment.

From The Wall Street Journal • Apr. 9, 2026

Apart from its serial nature and arc, the new season/series doesn’t do anything new, doesn’t attempt to update its year 2000 operating system to 2026 standards.

From Los Angeles Times • Apr. 9, 2026

The preview version of Anthropic’s new Mythos model “has already found thousands of high-severity vulnerabilities, including some in every major operating system and web browser,” the company said in a blog post.

From MarketWatch • Apr. 7, 2026

‘But mine works on a different operating system from other people’s. And my wiring’s different too.’

From "The London Eye Mystery" by Siobhan Dowd