Proprietary software or closed source software is software within a licensing agreement that allows only authorized users to privately modify, copy or republish with restrictions. Most companies or tech that wants to keep their code/products private use this type of software more to maintain their brand and user experiences.
Software within a licensing agreement that allows code to be shared, viewed and edited by outside users, organizations or on the internet. This gives the code the ability to iterated by other developers and give other users who may be looking to do something similar, to see what and how code has been written or modified over time.
In 1997 Eric Raymond, a free software advocate compared the styles of The GNU Project and the Linux project before they were combined. The GNU project was a project that would create free operating systems and build a software community. Source code was developed by a small team of developers and was distributed freely with every new release. The Linux project was source code developed over the internet in public. This movement really took off in 1998, when Netscape decided to open source the code for Netscape communicator. Open sourcing this code later resulted in Mozilla Firefox to be completely open source and free. Proprietary software has always been something that was there when IBM sold its first computer.