Answer: keeps confidential documents secure,
displays a GUI, allocates the computer's resources, and retrieves files
Step-by-step explanation:
The operating system can be defined as the software installed in the system that provides the information and services to the users by controlling the hardware, software resources, and regulates the computer programs. It runs the applications and programs in the system, displays the graphic user interface for the services, stores, manipulates, and retrieves files. It prevents the unauthorized access to the data and programs by using passwords thus provides the security to the system and documents.