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

---

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

---

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.

---

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.

---

Etymology

Origin of operating system

First recorded in 1960–65

Example Sentences

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

Networking giants Cisco and Broadcom are taking part in the project, along with the Linux Foundation that promotes the free, open-source Linux computer operating system.

From Barron's • Apr. 7, 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 each of those bodies still needs a brain - an operating system, or software, that tells the various bits of metal what to do.

From BBC • Apr. 7, 2026

I’d been able to coax it back to life by replacing its system memory and reloading the stone-age operating system.

From "Ready Player One: A Novel" by Ernest Cline