How do permissions control access to files in an operating system?

Permissions are a fundamental component of file security in an operating system, governing how files can be accessed and modified by users. The correct choice emphasizes that permissions specify which users can perform certain actions on files, such as reading the contents, writing new data, or modifying existing data. This form of access control is crucial for maintaining data integrity and security, ensuring that only authorized users can alter or view sensitive information.

For instance, in many operating systems, permissions are structured in a way that can distinctly alter the level of access for different users or groups. This granularity allows for collaborative environments where multiple users may need varied access levels based on their roles. Overall, permission settings enhance security and user management within an operating system, thus making it an essential feature in protecting data.

Other options, while they propose forms of access control, do not accurately reflect the primary purpose of permissions in an operating system's functionality and structure: unrestricted access, encryption with passwords, and limited access strictly to administrators do not encapsulate the broader, nuanced function that permissions serve in managing user rights to files.