  The basic workings of inflationary models are summarized, along with the
arguments that strongly suggest that our universe is the product of inflation.
It is argued that essentially all inflationary models lead to (future-)eternal
inflation, which implies that an infinite number of pocket universes are
produced. Although the other pocket universes are unobservable, their existence
nonetheless has consequences for the way that we evaluate theories and extract
consequences from them. The question of whether the universe had a beginning is
discussed but not definitively answered. It appears likely, however, that
eternally inflating universes do require a beginning.
