Operating System

An Operating System acts as a communication bridge (interface) between the user and computer hardware. The purpose of an operating system is to provide a platform on which a user can execute programs in a convenient and efficient manner. 

Example: Just like a boss gives orders to his employee, in a similar way we request or pass our orders to the Operating System.

Some popular Operating Systems include Linux Operating System, Windows Operating System, VMS.

Following are some of important functions of an operating System.

• Memory Management
• Processor Management
• Device Management
• File Management
• Security

 

Memory Management

• The operating system controls the primary memory or main memory.
• Main memory is fast storage and it can be accessed directly by the CPU.
• A program must first be loaded into the main memory before it can be executed.
• When the program is completed, the memory region is released and can be used by other programs. Therefore, there can be more than one program present at a time. Hence, it is required to manage the memory.

For memory management, the OS performs the following tasks:

• Allocates and de-allocates the memory.
• Keep a record of which part of primary memory is used by whom and how much.
• Distributes the memory while processing.

 Processor Management

A process is defined as a sequence of instructions are executed in a predefined order. In simple words, any program that is executed is termed as a process.

• Every software that runs on a computer, whether in the background or in the foreground, is a process. 
• When more than one process runs on the system the OS decides how and when a process will use the CPU.  This is called process scheduling.
• Allocates and de-allocates processor to the processes.

Device Management

An OS manages device communication through respective drivers.

The following activities are performed by the operating system for device management.

• Keeping track of all devices connected to the system.
• The OS designates a program that is responsible for every device which is called the Input/output controller.
• It decides which process gets access to which device and for how long. It then allocates the devices in an effective and efficient way and de-allocates devices when they are not required.

File Management

• A file system is organized into directories for efficient or easy navigation and usage. These directories may contain other directories and other files. 
• An Operating System carries out the following file management activities. It keeps track of where information is stored, user access settings and status of every file, and more… These facilities are collectively known as the file system. 

 

Security

The operating system uses password protection to protect user data and similar other techniques. it also prevents unauthorized access to programs and user data.