It is a program on which application programs are executed

It acts as an interface between the user & the computer

Functions

• Security: OS uses password protection & other such techniques to protect user data
• Control over system performance: Monitors & records overall performance of the overall system to help in improving performance
• Job accounting: OS keeps track of time & resources used by various tasks & users
• Error detecting: OS detects errors, preventing from the malfunctioning of the computer system
• Coordination between software & user: OS coordinates & assigns compilers, interpreters and different other softwaes to various users of the computer system
• Memory management: OS anages different functionalities of primary memory or main memory, like, managing process allocation and requests, along with deadlock management
• Process management: In multi-programming, OS manages the order and access time of each process to access the processor
• Device management: OS manages differnt parts of a computer via their respective drivers
• File management: OS manages differnt files via a definite system, by keeping the files in different directories for efficient & easy usage