This picture is about the different parts of  volcanoes. It shows how an volcano can erupted. These are the definitions of the different parts of volcano:

Vent- An opening allowing the passage of air. Ash Cloud- The powdery residue left after burning. Dike- The barrier or obstacle of a volcano. Sill- Slab of stone at the foot of the volcano. Flank- The side of a volcano. Lava- Matter flowing from a volcano that solidifies as it cools. Crater- Mouth of a volcano. Conduit- Channel or pipe conveying liquids such as lava. Summit- Highest point; apex Throat- Entrance of a volcano.