What are the three main volcanoes?

There are three main types of volcano - composite or strato, shield and dome.

Composite

Composite volcanoes, sometimes known as strato volcanoes, are steep sided cones formed from layers of ash and [lava] flows. Composite volcanoes can rise over 8000 feet. Examples of composite volcanoes include Mount Fuji (Japan), Mount St Helens (USA) and Mount Pinatubo (Philippines).

 
A simple cross section through a composite volcano

When composite volcanoes erupt they are explosive and pose a threat to nearby life and property.

Shield

Shield volcanoes have gently sloping sides and are formed from layers of lava. Eruptions are typically non-explosive. Shield volcanoes produce fast flowing fluid [lava] that can flow for many miles. Examples of shield volcanoes include the Hawaiian volcanoes. Although these eruptions destroy property, death or injury to humans rarely occurs.

Dome (Acid Lava Cones)

Acid [lava] is much thicker than [lava] which flows from shield volcanoes. Dome volcanoes have much steeper sides than shield volcanoes. This is because the lava is thick and sticky. It cannot flow very far before ot cools and hardens. An example is Puy de Dome in the Auvergne region of France which last erupted over 1 million years ago.