GN4 tracks changes of content and objects in so called 'audit trail'.
Each time a GN4 object or content is modified, the system checks if its state attribute (if defined) has been modified, and in such a case it records its previous value in the object update audit trail (history) entry.
Related links
Audit trail of merged articles: see Merge content ot two or more articles.
Audit trail of wires: see Wires footprints.
Audit trail of pages: see Display page audit.
Display audit of articles/images on Tracking main tab