For the people who read the record. This page says what SmartApps put in your hands, what stays with other roles, and how a week runs.
The log is append-only and hash-chained; a correction is a new entry that refers to the old one.
Yes: the values shown and entered at the step, the app version, the access policies applied to the read.
On the engine: levels in sequence, alternates, delegates with both names logged, clocks and escalation; an override is its own logged step with a justification.
Tell us your role and one process; the demonstration runs the screens you would use, on data like yours.