What are volcaneous?

Answer 1

A volcano erupts because there is mass pressure under it. In a volcano there is hot, melted rock called lava. The hot lava produces gasses that build up underground until there is too much for the rock to contain, that makes the eruption. When there is too much, it bursts the volcano.

There are two types of eruptions. Non explosive and explosive. When they are explosive, it is caused by clouds of hot debris and gases.