An inauguration is a formal ceremony to mark the beginning of a major public leader's term of office. The "inaugural address" is a speech given during this ceremony which informs the people of his/her intentions as a leader. A famous inauguration speech is John F. Kennedy's.
Political inaugurations often feature lavish ceremonies, in which the politician publicly takes his or her oath of office in front of a large crowd of spectators. The equivalent ceremony in another jurisdiction may be called a "swearing-in". A monarchical inauguration is similar to what in another jurisdiction may be called a coronation or enthronement.
Other than personal inaugurations, the term can also refer to the official opening or beginning of an institution or structure, for example the inauguration of a new Canada–United States border crossing.