Michael

Tectonic plates are rocky plates that cover the earth's surface like a big shell.  They rub against each other and make friction.  The more they shift under each other, the further the continents move away from each other.  Besides for pulling apart they can also push together.  Then two or more continents will collide and push into each other and make big mountains.  The tallest mountains in the world are created by tectonic plates colliding. 

Underneath the tectonic plates there are other parts of earth.  There is a crust, a mantle made of very hot magma and finally, there is a core that is made of iron and other metals.  The heat rises out from inside the earth and comes out through the volcanoes.                            
Volcanoes erupt when hot magma rises and the volcanoes then it erupts!!!!!😃.
A volcano is a opening in the earth's crust. A volcano can be active😞 /  dormant😳 / extinct ⬅️ I'm happy it won't explode😄. A volcano is a Mountain