Both system fields provide a kind of “change history” — regarding the persons who have modified the document and the time of modification. However, there is an important difference…
Differences between these system fields
$UpdatedBy returns a list of all persons who have ever modified the document.In contrast to the
$Revisions field (= last modification timestamps), a new entry is only added if the active user name differs from the most recent entry in the field.Amazon Affiliate Link
