There are three types of tectonic plate movement :
Convergent plate movement
When two plates move towards each other they collide.As the plates collide some crust is destroyed.Hence it is also called as destructive plate boundaries.
Divergent plate movement
When two plates move away from each other they are called diverging.The magma from the mantle underneath the crust rises up, cools and solidifies and thus new crust is formed.Hence it is also called constructive plate boundaries.
Transform plate movement
When two plates move horizontally past each other.They form transform boundary. When they occur, crust is neither created nor destroyed along it.Hence they are also called conservative plate boundaries.