Simplify the following text for a Grade 13 native English-speaking person.
Original: Investiture , from the Latin ( preposition in and verb vestire , ` dress ' from vestis ` robe ' ) is a rather general term for the formal installation of an incumbent ( heir , elect of nominee ) in public office , especially by taking possession of its insignia .
Simplified: Investiture means the formal installation of somebody ( heir , elect of nominee ) in public office by formally giving him the `` insignia '' .