A crater is a funnel-shaped hollow located on the top of the volcanic cone, formed by explosion or collapse of the summit. A crater is sometimes found on the flank of the volcano instead of at the top. The bottom of the funnel opens into a channel or pipe (conduit) through which the erupted material finds its way to the surface.
A crater can also be formed meteorite impacts. The size and shape of these craters may be close to those of volcanic origin.