Operating System : Function

1)User Interface

• In most operating system today, the user interface includes the windows, menus and method of interaction between user and the computer.
• Prior to graphical user interfaces (GUIs), all operation of the computer was performed by typing in commands.
• Not at all extinct, command-line interfaces are alive and well and provide an alternate way of running programs on all major operating systems.
• Operating systems may support optional interfaces, both graphical and command line.

2) Job Management

• Job management controls the order and time in which programs are run and is more sophisticated in the mainframe environment where scheduling the daily work has always been routine. 
• In a desktop environment, batch files can be written to perform a sequence of operations that can be scheduled to start at a given time.

 


3) Task Management

• Multitasking, which is the ability to simultaneously execute multiple programs, is available in all operating systems today.
• Critical in the mainframe and server environment, applications can be prioritized to run faster or slower depending on their purpose.
• In the desktop world, multitasking is necessary for keeping several applications open at the same time so user can bounce back and forth among them. 

 

4) Data Management

• Data management keeps track of the data on disk, tape and optical storage devices.
• The application program deals with data by file name and a particular location within the file.
• The operating system's file system knows where that data are physically stored (which sectors on disk) and interaction between the application and operating system is through the programming interface.
• Whenever an application needs to read or write data, it makes a call to the operating system.

5) Device Management

• Device management controls peripheral devices by sending them commands in their own proprietary language.
• The software routine that knows how to deal with each device is called a "driver," and the OS requires drivers for the peripherals attached to the computer.
• When a new peripheral is added, that device's driver is installed into the operating system. 

6) Security

• Operating systems provide password protection to keep unauthorized users out of the system.
• They also provide backup and recovery routines for starting over in the event of a system failure.