What do tectonic plates refer to?

Tectonic plates refer to large, moving pieces of the Earth's crust that float on the semi-fluid asthenosphere beneath them. These plates can vary in size and shape, and their movements are driven by the heat from the Earth's interior. As they interact at their boundaries, they can cause geological phenomena such as earthquakes, volcanic activity, and the formation of mountain ranges. This dynamic nature of tectonic plates is fundamental to understanding the processes that shape the Earth's surface and influence geological activity.

The other options describe unrelated concepts. Non-moving sections of the Earth do not accurately characterize tectonic plates, as they are defined by their movement. Pieces of the Earth's atmosphere are not connected to the geological structure of the planet. Lastly, the water bodies of the Earth are completely separate from the composition or characteristics of the tectonic plates. Thus, the notion of tectonic plates specifically relates to the movement and interaction of the Earth's crust.