TempoWeave saves copies of your weaving design in case you ever need to refer to, or retrieve a prior version of your draft.
Versions (snapshots) of your weaving design are saved each time you save your design as well as when certain transformative functions are performed, such as Create Double Cloth. Prior versions of your draft can be accessed by clicking the version history icon. The date and time the snapshot was taken is shown, along with the path and file name. Any of the versions can be selected and opened; if needed, they can be saved as a new name or overwrite the current version of your draft.
Version history is based on the name you give your draft, not the file location. If you have multiple designs with the same name, you'll see all of those designs in the version history. They can be distinguised by the location. The reason TempoWeave works this way is to preserve version history even if you move your file to another directory.