An operating system is an intermediary program between computer user and the computer hardware. This computer user can also be just another software running on the operating system or another computer or device. So basically, operating systems are computer programs that let other computer programs or humans communicate with the hardware of the computers.
Purpose of Operating Systems
The purpose of an operating system is create such an environment for the user where the user can execute other programs and those other programs can make use of the computer hardware and then can return output to the user.
Goals of Operating Systems
The primary goal of an operating system is to let the computer user use the computer in a convenient way. A secondary goal is to make use of the computer hardware in an efficient manner. A computer has roughly four components; the hardware, the operating system, the application programs and the users. Users use application programs to command tasks, while the application program uses the operating system to use the hardware of the computer to execute the command and the operating system finally uses the hardware to do task. After these steps, it go in the reverse director back to the user.
Roles of Operating Systems
Operating systems play many roles such control program. Operating systems control the computers and the application programs both. An operating system controls all the IO devices attached to the computer, all the installed applications, network communication etc. and their executions. An operating system ensures that nothing is using the computer in an improper way. To control programs and IO devices, operating systems also manage the resources of the computer, like memory, hard disk, processor power, network traffics etc., so that no specific program blocks a resource in a way that it becomes difficult to maintain the efficiency of the computer resources. Thus an operating system is also a resource allocator.
Operating systems were created to make it convenient for the user of the computer to actually use the computer to solve problems. Operating systems exists so that it is easier to computer with them than without them.