A local edit history of a file is maintained when you create or modify a file. Each time you edit and save the file, a copy is saved so that you can replace the current file with a previous edit. You can also compare the contents of all the local edits. Each edit in the local history is uniquely represented by the date and time the file was saved.
Only files have local history; projects and folders do not have a local history.
Replacing a resource with local history
Comparing resources with local history
Setting local history preferences
Creating a version of a project