How do plate tectonics relate to the formation of Volcanoes? Which type of plate margin commonly form Volcanoes?

There are mainly two types of plate tectonics. There is destructive where part of a plate goes under ground and becomes apart of the magma, and the other is constructive where both plates aren't destroyed, there maybe creation of the plates or rubbing against each other.
The destructive plate margin deposits some sea water and other things into the magma. The heat makes it expand which increases the pressure. The magma escapes (more like explodes) to the surface. This creates the volcano.