Which term refers to software that cannot be modified or shared without authorization?

The term that refers to software that cannot be modified or shared without authorization is closed-source. Closed-source software is proprietary, meaning that the source code is not made available to the public. This restricts users from altering the program or sharing it freely, as doing so would violate the software's licensing agreements.

In contrast, open-source software allows users to view, modify, and distribute the source code, fostering collaboration and innovation. Public domain software is free of copyright restrictions, allowing anyone to use, modify, and distribute it without permission. Freemium describes a business model where software is provided for free with basic features, while advanced features require payment; it does not inherently address the modification or sharing restrictions.

Understanding these distinctions is crucial for managing software rights and licenses effectively, particularly in environments dealing with proprietary applications.