How would I explain the word inauguration to 5th graders

Inauguration is a special event to mark:

(1) the start of a public official's term in office or;

(2) an opening of a civic area, organization or project.

The President and Vice President swear to do their jobs to the best of their abilities and to be faithful to the Constitution. There is a huge parade up Pennsylvania Avenue to the White House after the official ceremony ... Inauguration Day is when the incoming President of the United States takes the oath of office.