What type of software can be purchased from a vendor and cannot be modified?

Proprietary software is a type of software that is owned by an individual or a company. This ownership means that the source code—the underlying programming that makes the software work—is not made available to the public. Vendors of proprietary software typically provide the software under a licensing agreement, allowing users to use it under certain conditions but not to modify, distribute, or access the source code.

This distinction is essential because proprietary software is often developed for commercial purposes and is structured to generate revenue for the company that owns it. Users benefit from technical support, regular updates, and security patches, but they are restricted from altering the software or its components.

In contrast, hybrid software can allow for some modifications or integrations, shareware is typically distributed for free with limited features or trial periods and encourages users to pay for full access, while utility software refers more generally to tools that help manage or tune computer hardware, operating system, or application software.