A volcano is an opening in the Earth’s crust.  It is shaped like a point, with a hole in the middle.  Sometimes a volcano can erupt.  When it erupts, hot lava comes out of the volcano.  Gases and ash can also come out of a volcano.

Inside the Earth is rock and metal.  Some of the rock is so hot it has melted.  This rock is called magma.

Hot melted rock can come out of a volcano.  This melted hot rock is called lava.  Lava is the same as magma.  Magma is hot melted rock inside the Earth.  A volcano can shoot magma out of it.  Magma is called lava when it is outside of the Earth.   When lava cools it becomes rock.

A volcano can shoot out lava. This is called to erupt.  

Lava is hot melted rock that comes out of a volcano.  When it cools the lava becomes hard rock.  This rock is called volcanic rock.