What are the functions of System calls? - Windows Programming

What are the functions of System calls?

- The system calls are used to read the process and allow the handler to take the action over it.

- It allows the handler to save the state of CPU and perform the processing of the event.

- It also used to restore the state of the CPU by switching back to the user mode and let the CPU resume the execution of the program.

- The system call calls the Windows API that is in functional state and it triggers an interrupt that makes the switch from CPU to kernel mode.

- It executes the API function that processes the event and switches back to the user mode.