1.1 Operating System Functions

	The operating system is the program that manages the running applications and acts as the interface of these
	these applications and the computer hardware resources. The operating system can have several goals as
	described in the following subsections.

The operating system as a user/computer interface

The operating system layer is considered the interface between the hardware and software layers.

	The application programs usually use high level programming languages that do not need to use the complex
	hardware structure.

	The operating system has libraries and system calls that implement the interface between these application
	programs and hardware components.

The operating system typically provides services in the following areas (Stallings, William, (2011)):

		Program development.
		Program execution.
		Access to I/O devices.
		Controlled access to files.
		The operating system as resources manager.

1.1 Operating system functions

	The computer system has resources such as processor, memory, and I/O devices.
	The application programs need to use these resources during the life time of these applications.
	The operating system acts as a resource manager that controls which resource is assigned to which
	application program.

User convenience

	There are different facets of user convenience that the operating system has to offer to the users. Earlier
	operating systems had to offer simpler interfaces to the users.
	Modern operating systems have to offer easier interface such as graphical user interface. Advanced
	operating systems have to support features such as parallel computing and Web-oriented features.