What is interactive of operating system?

The user interface is the "interactive" component.

Windows is an OS that allows its user to interact with a graphical user interface, while e.g. Unix can use a command shell such as "Bourne Shell" for the user to type commands and get them executed.

A batch oriented operating system does not allow the user to interact - answer "yes" or "no". You started a pile of punched cards and processed them to the bitter end, you received the output as a printed file, and a list of failed entries. Then you changed a card or hundred, and ran them all again. Here you have no interaction.

A non-user interaction is process control systems such as SCADA, where sensors interface to the system, and the engineers can give commands to control what goes on. But some of these have no users that interact - like robots.