Boundary types refer to the different ways in which geological boundaries are classified based on tectonic plate interactions. The three main types are divergent boundaries, where plates move apart, creating new crust; convergent boundaries, where plates collide, leading to subduction or mountain formation; and transform boundaries, where plates slide past each other, causing earthquakes. Each boundary type plays a crucial role in shaping the Earth's surface. For instance, divergent boundaries often form mid-ocean ridges, while convergent boundaries can create deep ocean trenches. Understanding these boundaries helps scientists predict geological events and comprehend the planet's dynamic nature.