List of System Components:
1. Process management
2. Main memory management
3. File management
4. I/O system management
5. Secondary storage management
Process Management: The operating system manages many kinds of activities ranging from user programs to system programs like printer spooler, name servers, file server etc.
Each of these activities is encapsulated in a process.
A process includes the complete execution context (code, data, PC, registers, OS resources in use etc.).
The basic unit of software that the operating system deals with in scheduling the work done by the processor is either a process or a thread, depending on the operating system.
It’s tempting to think of a process as an application, but that gives an incomplete picture of how processes relate to the operating system and hardware.
The application you see (word processor or spreadsheet or game) is, indeed, a process, but that application may cause several other processes to begin, for tasks like communications with other devices or other computers.
There are also numerous processes that run without giving you direct evidence that they ever exist. A process, then, is software that performs some action and can be controlled by a user, by other applications or by the operating system.
It is processes, rather than applications, that the operating system controls and schedules for execution by the CPU. In a singletasking system, the schedule is straightforward.
The operating system allows the application to begin running, suspending the execution only long enough to deal with interrupts and user input.
The five major activities of an operating system in regard to process management are
1. Creation and deletion of user and system processes.
2. Suspension and resumption of processes.
3. A mechanism for process synchronization.
4. A mechanism for process communication.
5. A mechanism for deadlock handling.