When NeuShield Data Sentinel is installed it adds a barrier to your protected files preventing them from direct changes. When an application tries to modify a protected file, it gets redirected and the file modification is stored on an overlay, keeping the original file intact. Later, if you want to go back to the original file you can simply delete the data on the overlay. This process of deleting data on the overlay is called reverting changes.
NeuShield Technical Whitepaper
