.. _parts:

Parts of an Operating System
==============================

There are 4 broad tasks performed by an operating system.

.. describe:: Process Management

   A :term:`process` is an executing program. It has its code, data, a
   certain set of resources allocated to it, and one or more threads of
   execution through the code. The OS manages the allocation of resources to
   these processes, and also provides system calls to manage these
   processes.

.. describe:: Memory Management

   Memory must be shared between the OS and an application program. The OS
   must manage the allocation of memory to processes and control the memory
   management hardware that determines which memory locations a process may
   access.

.. describe:: File System Management 

   Computers process information that must be transmitted, processed, or
   stored. File systems are an abstract organized collection of file system
   objects. The OS provides primitives to manipulate these objects.

.. describe:: Device Management

   Information is sent through a computer's input and output devices.
   Processes access these devices using the :term:`system call` interface. The
   OS tries to manage said devices in a manner that makes them efficiently
   shared among all processes requiring them.  A :term:`system call` is a
   programming interface to the services provided by the OS, typically written
   in C/C++.