What is a Volcano?

A volcano is a crack or vent in the earth's crust that ejects molten rock (lava when it's above ground, magma when it's below ground), rock fragments, gases, ashes, etc. from the earth's interior; a volcano is active while it is erupting, dormant when it hasn't erupted for a long period of time, or extinct, which is when all activity has finally ceased.

How are Volcanoes formed?

Volcanoes start out as magma, which was talked about under "What are Volcanoes?". Magma results from the extreme heat of the Earth's interior, which can actually cause rocks to melt! When the rock melts it produces gas and becomes magma. The gas-filled magma slowly rises towards the earth's surface because it is lighter than the solid rock around it.

Where are Volcanoes found?

Volcanoes are found on almost every continent on earth(the exception is Australia). Many volcanic eruptions occur under the deep oceans or in places where very few people live, but once every few years a major eruption hits a heavily populated area.