ABSTRACT
The operating system (OS) is the master program that runs on one's computer, be it a smartphone, tablet, laptop, or desktop. It brings life to the innate electronic hardware components and orchestrates all activities on a computer. Typically, an OS consists of a kernel and a set of system programs. The kernel controls hardware and supports fundamental services, such as input/output (I/O) control, concurrent program execution, memory management, file services, and network interfaces. In an OS, the term process or task refers to a program that has started execution but has not finished. A key OS kernel service is process control, coordinating and managing these concurrent processes. While in kernel mode, the process has access to both user space and kernel space. The process switches back to user mode upon return of the system call. In addition to the kernel, modern OS usually also supply a set of system programs to make the computer usable and functional.
