A „closed source software solution“ is a solution whose source code is not publicly available and is owned by a single organization. This means that the user can’t access, modify, or distribute the source code. This is in contrast to „open source software“, whose source code is freely available to anyone, allowing users to modify, distribute, and improve it.

The disadvantage of Open Source Software compared to Closed Source Software is the dependence on the development community for the further development of the product. If, for whatever reason, that community loses interest in the product, that contribution will decrease or the project will be discontinued. With Closed Source Software, there is almost always an interest of the developer to keep the software up-to-date and thus continue to develop it. Retailware is „Closed Source Software“.