The operating system basically helps the user to interact with the hardware plus for other programs to use hardware to interact with the user or other programs. Mainly all programs need an OS because they rely on the OS interpreting their commands and then sending instructions to the hardware.

Some programs can be run without OS; most assembly programs contains feature to run without an operating system. The two reasons for an OS to exist are: to enable the user to perform file system tasks and adjust hardware, and to make programming easier.