State three functions of an operating system.

1. Memory management: The operating system is responsible for managing the computer's memory, allocating memory to different processes and ensuring they do not interfere with each other's memory space.

2. Process management: The operating system oversees the execution of processes, scheduling them for execution and managing their resources. It also handles the creation and termination of processes.

3. File management: The operating system organizes and manages files stored on the computer, including creating, deleting, moving, and accessing files. It also controls access permissions to files and directories.