Apache™ Subversion® (SVN) is a free, open source version control system that operates according to the client/server model.
An SVN server is usually installed on a central computer and it manages the data of the SVN repository in a database. An SVN repository is simply directory tree that contains your CODESYS projects. The SVN server makes client access available to the stored data and the CODESYS projects.
The project data is available as a working copy on your workstation computer, which acts as the client. When you open your project, CODESYS SVN displays the SVN status of all objects in the object tree and provides SVN commands. Then you can use version control to continue developing your project in CODESYS.