Final answer:
The crustal movements in Earth's crust are collectively known as tectonic activity. Tectonic plates move and interact with each other at their boundaries, leading to geological phenomena like mountain building and volcanic eruptions.
Step-by-step explanation:
The crustal movements of various kinds in the Earth's crust are collectively called tectonic activity. Tectonic plates, which are composed of Earth's crust and the uppermost part of the mantle, are constantly moving and interacting with each other at their boundaries. These interactions include plate divergence (moving apart), convergence (moving toward each other), and transform boundaries (sliding past each other). These activities contribute to geological phenomena such as mountain building, volcanic eruptions, earthquakes, and the reshaping of the Earth's surface.