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

"Mythos Preview has already found thousands of high-severity vulnerabilities, including some in every major operating system and web browser," Anthropic claimed on 7 April.

From BBC • Apr. 17, 2026

The 1998 bug in the OpenBSD operating system was one of thousands Mythos found last month.

From The Wall Street Journal • Apr. 14, 2026

For example, Anthropic said that in one popular operating system it tested, used by thousands of companies including Netflix and Sony, Claude Mythos found a flaw that had existed undetected for 17 years.

From Los Angeles Times • Apr. 10, 2026

On the other side of the business, BlackBerry’s QNX real-time operating system for cars, robots, and other physical machinery has become the company’s core growth driver.

From Barron's • Apr. 9, 2026

The first version of the Windows operating system launched in 1985, and the breakthrough version that made IBM PCs much more user-friendly—Windows 3.0—shipped on May 22, 1990, only six months after the wall went down.

From "The World Is Flat" by Thomas L. Friedman