Two-way sync
Two-way sync keeps two places the same by copying changes in either direction. In Data Transfers it is called Bidirectional sync.
Two-way sync keeps two places the same by copying changes in either direction: add, edit or delete a file on one side, and the same happens on the other. If the same file changes on both sides between runs, that's a conflict.
In Data Transfers this is the Bidirectional sync operation: "Keep both sides in sync. Changes on either side propagate to the other. Conflicts logged."
The very first run for a pair of places needs the First run for this pair box ticked, so Storage Studio can record a starting point. Never tick it again on later runs for the same pair — it would overwrite one side with the other.
If you only want changes to flow one way, use one-way sync instead.
See also: Two-way sync and the First run box · Copy, Move, Sync or Two-way sync