Deep Space stores historical information about your project models, including quantities like Count, Area, Volume and Length.
The Variations App gives you a side-by-side comparison between two different 'data drops', or points in time.
This can be used to compare quantity changes between Tender models and current For Construction models (for example).
Generally, the Variations App needs the following:
Two 'data drops' created
The relevant 'data drops' are set in DS Command against the Project
Refresh the dataset
This article describes how you can work with Data Drops in Deep Space: