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What is Operating System?

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. . it enables the computer hardware to communicate and operate with the computer software.

An Operating System (OS) is an interface between a computer user and hardware. An operating system is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.

operating system initially loaded into the computer by a boot program. it manages all the other programs in a computer. The other programs are called applications or application programs. In addition, users can interact directly with the operating system through a user interface such as a command line or a graphical user interface (GUI).

Examples of operating systems :-

Microsoft Windows OS

Apple macOS

Linux

iOS :- Operating system used with the Apple iPhone and iPads.

Android :- Operating system used with Android compatible phones and tablets.

Chromium - Google operating system used with Chromebooks.

Following are some of important functions of an operating System.

Memory Management

Processor Management

Device Management

File Management

Security

Control over system performance

Job accounting

Error detecting aids

Coordination between other software and users

Memory Management :-

Memory management is the process of controlling and coordinating computer memory. Memory management resides in hardware, in the OS (operating system), and in programs and applications.

memory management involves components that physically store data, such as RAM (random access memory) chips, memory caches, and flash-based SSDs (solid-state drives). In the OS, memory management involves the allocation of specific memory blocks to individual programs as user demands change. At the application level, memory management ensures the availability of adequate memory for the objects and data structures of each running program at all times.

When the program requests a block of memory, a part of the memory manager called the allocator assigns that block to the program.

When a program no longer needs the data in previously allocated memory blocks, those blocks become available for reassignment. This task can be done manually (by the programmer) or automatically (by the memory manager).

Keeps tracks of primary memory, i.e., what part of it are in use by whom, what part are not in use.

In multiprogramming, the OS decides which process will get memory when and how much.

Allocates the memory when a process requests it to do so.

De-allocates the memory when a process no longer needs it or has been terminated.

Processor Management :-

In multiprogramming environment, the OS decides which process gets the processor when and for how much time. This function is called process scheduling. An Operating System does the following activities for processor management −

Keeps tracks of processor and status of process. The program responsible for this task is known as traffic controller.

Allocates the processor (CPU) to a process.

De-allocates processor when a process is no longer required.

Device Management :-

An Operating System manages device communication via their respective drivers. It does the following activities for device management −

Keeps tracks of all devices. Program responsible for this task is known as the I/O controller.

Decides which process gets the device when and for how much time.

Allocates the device in the efficient way.

De-allocates devices.

File Management :-

A file system is normally organized into directories for easy navigation and usage. These directories may contain files and other directions. An Operating System does the following activities for file management −

Keeps track of information, location, uses, status etc. The collective facilities are often known as file system.

Decides who gets the resources.

Allocates the resources.

De-allocates the resources.

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