Activity
In the Activity tab you can see a list of changes to the chosen data item.
For example, in the screenshot below you can see a list of changes to a data model:
If you click the + button (1 in screenshot) it expands a panel that displays information about a particular change.
You can see:
(2) the author of the change
(3) the difference between the old value before the change and the new value after the change
In addition, if you are a curator you can undo a change.