Glossary topic: 

A technological design or architecture whose configuration is unavailable to the public and may not be duplicated without permission from the designer or architect.

Proprietary technology is created for a given company's purposes.

Proprietary technology may be legally used only by a person or entity purchasing an explicit licence. Proprietary means 'privately owned and controlled', and hence software can remain proprietary even when source code is made publicly available, if control over use, distribution, or modification is retained.

See also Non-proprietary