Operating system is an interface of computer and applications. In other words we can say operating system is nothing,

it is collection of program that make the relations between computer hardware and software.

Operating systems allow user to interact with application what user need to execute.

Easy way to understand the definition of Operating System:

Example: We are at bus stop with Luggage. Want to cross the road , we need a help of e-riksaw ,we call them to put the luggage at the rickshaw and cross the road .Riksaw puller load our luggage and cross the road  .We can also cross the road with luggage , but here the work of rickshaw puller is like role of Operating system.

Its means we can execute our application directly with hardware but that are lengthy and time taking process.So we use operating as mediator that helps to run our application utilize the hardware.

Operating system’s most important function is resource management.

What is duty of Operating System ?

Operating System responsible to manage all resources.

By the managment of Operatinng System so more than one user can work simultaneously.Its also known as major responsibility to manage the CPU( Central Processing Unit) , Main Memory ,Secodary Memory and I/O Devices .

Stand For of IO Devices is Input /Output Device.

What is Input /Output Device ?

Definition of Input device : Device through which the date is entered into the system is known as input device. Eg: Keyboard

In other words we can say ,what the instruction given to the system is known as input device.

Definition of Output Device : Device through which the date is fetched from the system is known as output device . Eg.Printer,Monitor

What is result come from the system after instruction given to system that is known as output.

Do we  know Seconday memory is known as special type of Input and Output device.