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Operating system

nounverified·updated May 9, 2026

The software 'master control application' that runs the computer. It is the first program loaded when the computer is turned on, and its principal component, the kernel, resides in memory at all times. The OS sets the standards for all application programs (such as the mail server) that run in the computer. The applications communicate with the OS for most user interface and file management operations.

MWEFFIEC IT Examination Handbook - Audit, April 2012

Senses

ISACA Cybersecurity Glossary

A master control program that runs the computer and acts as a scheduler and traffic controller Scope Note: The operating system is the first program copied into the computer’s memory after the computer is turned on; it must reside in memory at all times. It is the software that interfaces between the computer hardware (disk, keyboard, mouse, network, modem, printer) and the application software (word processor, spreadsheet, e-mail), which also controls access to the devices and is partially responsible for security components and sets the standards for the application programs that run in it.

Federal Financial Institutions Examination Council (FFIEC) IT Examination Handbook Infobase, Glossary

A system that supports and manages software applications. Operating systems allocate system resources, provide access and security controls, maintain file systems, and manage communications between end users and hardware devices.

Wordset Dictionary

(computer science) software that controls the execution of computer programs and may provide various services

NIST SP 800-171r3attested usage pack match

No definition is given in NIST SP 800-171r3. The term is attested in use at 6 citations in that document; a definition is pending curation.

Classifications

Entity Type

System95%rule-basedr:entity.system.compute.v1
?unassignedlast reviewed

Sensitivity

unclassified

Information Class

unclassified

Variants

acronym
OS
synonym
OS
alternatephrasing
Operating System
plural
Operating systems
possessive
Operating system's
pluralpossessive
Operating systems'