A snapshot is a selected set of document objects in their current revision. A snapshot is used to unambiguously identify the state of the project e.g. at a project milestone or at a product release or as input for a review.
You can create a snapshot of the project or parts of the project at any time.
To create a snapshot, navigate to a chapter (i.e. via the Project Explorer) and select Set Snapshot from the drop down menu for the chapter. This will display a view where you may select what document objects and chapters that shall be included in your snapshot.
To create a snapshot of the complete project (including issues and reviews), select Snapshots -> Set Snapshot on All in the Navigation bar.