Using the local data stored in the .svn folder, the Subversion client is able to analyze the directory contents and identify all the files that are new, have been modified, or are missing since the last checkout or update operation was performed, and then generate a list of these changes.

When the commit operation is performed, new files are added to the repository, modified files are uploaded and stored next to their previous versions, while deleted files are tagged as no longer being part of the current project version. While some of these behaviors might seem strange, it's by preserving previous versions of files and even keeping files that are no longer part of a project that Subversion is able to let us navigate through a project's entire history.

While it is preferable to use the TortoiseSVN menu to mark files and directories for addition and to delete items that are no longer needed, it is also possible to perform these operations when the commit is about to take place, as we saw in the recipe steps.