EstateExec stores your data in the cloud (in encrypted format). Whenever you make a change to an estate, the "Save All" and "Cancel All" buttons in the top right will "light up" and become active, indicating that you have unsaved work.
Changes are not saved until you explicitly click the "Save All" button.
After you click "Save All", you will see a popup telling you that your data has been successfully saved.
You can cancel any changes you have not yet saved by pressing the "Cancel All" button in the top right, or by closing the browser window.
To protect you from accidentally forgetting to save your changes, if you try to close the browser window or navigate to a new page, EstateExec will warn you that you have unsaved changes, and ask you to confirm that you really want to abandon them.
See also Keyboard Shortcuts.