Operating system is the most important component of computer system which controls and operate the entire machine. Without operating system, you cannot use or control the computer.
The computer is useless unless it is provided the essential software that makes it ready to use. An operating system is a software, which makes the computer ready to use by a process called booting up.
In short:- Operating system is a system which creates an environment or interface through which the user can interact with Hardware and with application software.
Now understand in this way, if you want to use / control the web camera, mouse, hard disk, CPU, RAM or any component which is attached with the computer, we cannot communicate with all these devices / components since they interact electronically. Thus, in order to have communication with all these components which makes up the computer system, we need to devise a provision through which users can communicate or give commands to realize the desired output.
Application software are also very useful tools to automate our day to day work. Application software are the set of programs / set of instructions written by the programmer to achieve a specific output. For example, in order to automate day to day accounting process, we have tally and Busy software and if we want to browse the internet, we have to have Microsoft edge, google chrome and Mozilla Firefox etc as an application software. These software are designed specifically to run on operating system environment, that is why while downloading any software from the internet, website ask you to choose your operating system before initiating downloads.
Therefore, Operating system also acts as an mediator between user and application software and also with system hardware to create an coordinated work environment with each other.
A computer system / hardware cannot be operated without operating system. It is like a car without patrol/Fuel.
Examples of OS are:- Windows, MacOs, Linux, iOS, Android, Chrome OS etc.