A volcano is "An opening in the earth's crust from which molten rock and steam issue" This basically means that a volcano is a fissure in the crust of the earth. ( A large crack ) in which lava comes out.) The actual volcano is the mountain from which the lava and eruptions come from.

A volcano is very unpredible and can erupt in five different ways.
Hawaiian- When the volcano erupts and produces low clouds and very streamy lava. Very common.
	Peleean- When the volcano erupts in large chuncks and has a large cloud of ashes and gas go on ground level
Strombolian- When the volcano erupts in larget chucks called bombs. Also blocks, ash and cynders erupt. Is erupted fairly high into the air.
	Vulcanian- When the volcano has violent explosions that shoot out very thick lava and large lava bombs.
Plinian- When everything is shot very high into the air.
NOTE: The 5 volcanic eruptions were used from source 61,

Volcanoes can cause widespread damage with the lava and the clouds of rock and ash. Certain volcanoes have devistated cities, some in which the people never knew something was wrong. For more information about these volcanoes click [here].

Craters are the top of the volcano where the explosions occur and on the sides of volcanoes where small cracks are. Calderas are what remains of a crater after it was exploded in a previous explosion. Calderas are much larger than craters, probably one of the most famous being crater lake. Crater lake was created when Mt.Mazama colapsed over 6600 years ago. It was filled in with water from melting snow and rain accumilations.

You probably have seen some indiginous rock, which is really dried lava. There are three types of this dry lava:

Pahoehoe Lava

Pillow Lava

AA Lava

More information about how/why volcanoes erupt can be found [here]

Information about major past volcanoes can be found [here]

Volcano links can be found [here]

More volcano pictures can be found [here]