Definition - What does Proprietary Software mean?
Proprietary software is any software that is copyrighted and bears limits against use, distribution and modification that are imposed by its publisher, vendor or developer. Proprietary software remains the property of its owner/creator and is used by end-users/organizations under predefined conditions.
Proprietary software may also be called closed-source software or commercial software.
Techopedia explains Proprietary Software
Proprietary software is primarily commercial software that can be bought, leased or licensed from its vendor/developer. In general, proprietary software doesn't provide end users or subscribers with access to its source code. It can be purchased or licensed for a fee, but relicensing, distribution or copying is prohibited. Most software is proprietary software and is produced by an independent software vendor (ISV). The restrictions or conditions imposed by the vendor/developer on proprietary software is elaborated within the software's end-user license agreement (EULA), terms of service agreement (TOS) or other related use agreements. The user/organization must accept the agreement prior to installing or using the software. The software developer/vendor can take legal action against the end-user/organization for violating the EULA or TOS.