Their source of energy and heat is gotten from molten magma by geothermal reactions. And they both erupt, under increased temperature and pressure through vents, holes, cracks or any other form of outlet or passage into the earth surface.
No, geysers send up fountain like jets of water and steam. Volcanoes erupt lava.
No. Deimos is not a planet; it is a small moon. It does not have any volcanoes or geysers.
What I have learned in Earth Science I would say that there is many volcanoes and/or ice geysers.
Iceland.
volcanoes & geysers
geysers they both shoot something out
Neptune.
volcanoes and geysers
geothermal
The North Island.
geothermal
geothermal