Convergent Boundary is also called a destructive plate boundary because of it's subduction and it actively deforms its region where two or more tectonic plates or fragments of the lithosphere move toward one another and collide. When continental and oceanic plates collide the thinner and more dense oceanic plate is overridden by the thicker and less dense continental plate. The oceanic plate is forced down into the mantle in a process known as subduction. As the oceanic plate descends it is forced into a higher temperature environments. At depth about 100 miles (160km) materials in the sub ducting plate begin to approach their melting temperatures and a process of partial melting begins.
Divergent Plate Boundary (Also known as a constructive boundary or extensional boundary) is a feature that exists between two tectonic plates that are moving away from each other. When a divergent boundary occurs beneath oceanic lithosphere, the rising convection current below lifts the lithosphere producing a mid-ocean ridge. Extensional forces stretch the lithosphere and produce a deep fissure. When the fissure opens, pressure is reduced on the super-heated mantle material below. It responds by melting and the new magma flows into the fissure. The magma then solidifies and the process repeats itself.
A Transform Boundary (Also known as conservative plate boundary) and since these faults neither create nor destroy lithosphere, its a type of fault who's relative motion is predominately horizontal, in either a sinistral (left lateral) or dextral (right literal) direction. Transform Faults can be distinguished from the typical strike-slip faults because the sense of movement is in the opposite direction. A strike slip fault is a simple offset, however, a transform fault is formed between 2 different plates, each moving away from the spreading center of a divergent plate boundary.