When a volcano erupts it does not just simply erupt out of nowhere and then that's the end of it. The eruption of a volcano is a process. First of all a volcano is a way for magma from within the Earth to escape. When pressure from gases gets too great a volcano will erupt so that the built up magma under pressure has somewhere to go. After the volcano erupts the magma becomes lava and it begins to cool down once it has reached the surface.
Lava and volcanic ash can have a profound effect on the area around the volcano and it can destroy people’s homes as well. When the lava all cools down and everything is returned to normal the process will start all over again with gases building up that will eventually lead to another eruption.