What are tectonicsplates?

Answer 1

Tectonic plates.

Tectonic plates are plates underneath Earth's surface that move very slowly. There are oceanic and continental plates. Of course, oceanic plates are plates under the ocean, and continental plates are plates underneath ground, or continents. Each of the plates carry the things above them, land or ocean. When two continental or oceanic plates collide, it causes a fold in Earth's surface, and an earthquake. Now, when a continental plate draws near and nearly collides with an oceanic plate, something called subduction occurs. Subduction is basically when the oceanic plate dips down below the continental plate, causing a trench.