The term Facts was introduced in fh Version 3 to cover Events and Attributes.
At the same time Fact Sets were introduced to allow the management and handling of Facts both Custom and Standard.
These are shown on the Property Box Dialogue: Individuals: Facts Tab via the Show Timeline Facts button and governed by the Tools > Preferences > General > Timeline Facts command.
These were introduced in fh Version 6 to allow multiple Individuals to be linked to one Fact.
These are a special class of standard GEDCOM facts associated with the Church of the Latter Day Saints. They are only managed on the Property Box Dialogue: Individuals: All Tab and cannot be customised.