Another category classifying different types of volcanoes is based upon how violent they are during explosion which is a consequence of build up of gasses and pressure in magma. Here are most common eight types:

Icelandic - lava flows gently from the fissure, usually on flat slopes

Hawaiian - there is a small vent through which small amounts of lava flow

Strombolian - usually small but frequent eruptions occur

Vulcanian - this type is less frequent than Strombolian but more violent

Vesuvian - it has a long period of inactivity but right after it erupts with enormous power

Krakatoan - has got exceptionally violent explosion which might remove the peak of its cone

Pelean - very violent erutionis accompanied by pyroclastic flows which contain glowing cloud

Plinian - large amounts of lava and pyroclastic are ejected