What is it called when 2 plate collide?

What happen when 2 plate collide?

If two tectonic plates collide, they form a convergent plate boundary

This process is called subduction.

Convergent Boundaries

The place where two plates come together, or converge, is called a convergent boundary. When two plates converge, the result is called a collision. When two plates collide, the density of the plates determines which one comes out on top.