What is the purpose of a system call in an operating system?

The purpose of a system call in an operating system is to request services from the operating system's kernel. When applications need to perform tasks that require higher privileges—such as managing hardware resources, accessing files, or communicating over a network—they cannot directly interact with the hardware or core aspects of the operating system. Instead, they use system calls as an interface to safely and effectively request those services.

The kernel, which operates at a lower level and has unrestricted access to the system's resources, processes these requests. This allows user applications to perform complex operations while maintaining the security and stability of the overall system. Through system calls, operating systems can enforce access control, manage memory, handle input/output operations, and more, ensuring that multiple applications can run simultaneously without interfering with each other or with the hardware.

Other choices, while they involve important operations within an OS, are not the general purpose of system calls. Initiating a system shutdown and performing a network operation may require system calls, but they do not define what a system call is. Bypassing hardware limitations is more related to the capabilities of the OS itself rather than the specific mechanism of a system call. Thus, the primary role of a system call is to facilitate communication between user applications and the