Is lava dome a type of volcano?
Not exactly. Some volcanoes do consist of simply a lava dome, but most lava domes are found in or on stratovolcanoes.
a dome volcano is not the same as a cone volcano. a dome volcano is a type of volcano, is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Usually it extrudes very slowly, but constantly. A cone volcano has an appearance of an upside-down funnel with a hole in the top which the lava shoots out of.
I don't know about viscous, but a lava dome is a steep-sided dome of thick lava extruding from a volcanic vent. a viscous lava dome is when the lava from the volcano contains alot of silica. Viscous=sticky. So the lava cools quickly of the sides of the volcano. And often a viscous lava dome volcano is explosive.