When the page text changes, the system automatically increments the version number and keeps the previous version of the page. A new version is created only for changes made at least a minute apart. This avoids an excessive number of versions while the page text is being typed.
The "Versions" module lists the page versions compared with the current version. This shows what changed between the current version and the other versions of the page:
Each version shows its number, the differences from the current version, the author, and the date and time the version was created (that is, when the changes were made).
You can view the full text of a page version with the "Version text" item in the context menu.
If needed, you can apply (restore) any version of the page. The current version is kept and remains available for viewing or use in the "Versions" module. The previous version replaces the current one, but you can still restore the current version.