Revision History
The revision history view shows all edits that have been made to the family tree.
The list view shows the edits grouped by "transactions". A transaction is a group of one or more additions, deletions, or changes to Gramps objects. For instance, adding a new family with two existing persons as father and mother generates a transaction with one added family object and two modified person objects (because they contain the link to the new family object).
Clicking on a transaction opens the transaction detail view. It contains the list of individual additions, deletions, and updates by Gramps object.
Selecting an indivdial change opens a view of the raw JSON representation of the Gramps object with additions and deletions highlighted in green and red, respectively.