CQ5 allows you to save versions of your work in case you need to revert back to a certain point in your workflow. To create a version:

• Click on the Versioning icon (which looks like a clock face) in the upper toolbar of the Sidekick. The Create Version tab will open. Click the More button. Here you can add a Label to identify your version, and fill in any appropriate comments in the Comment section.
• Then click Create Version. A menu bar will drop down from the upper right of your screen confirming your version with the Label name.
  

• Click on plus sign (+) at the end of the Restore Version tab. To see the differences between your versions, check one of the version and click the Diff button. To restore a previous versions, click the Restore button.