Closed source, or proprietary programs are
|“||those whose source code is not made available and can only be altered by the software manufacturer.||”|
"In the case of closed source software, updates to a program are usually distributed in the form of a patch or as a new version of the program that the user can install but not alter. Some examples of closed source software include Microsoft Word and Corel WordPerfect. The majority of software products most commonly used, such as operating systems, word processing programs, and databases, are closed source programs."