Crust types refer to the different layers of the Earth's surface, primarily categorized into two main types: continental crust and oceanic crust. The continental crust is thicker and less dense, primarily composed of granitic rocks, while the oceanic crust is thinner and denser, mainly made up of basaltic rocks. These differences affect the way they interact with tectonic plates. The Earth's crust is also divided into various geological features, such as mountains, valleys, and plains. These features are shaped by processes like erosion, sedimentation, and tectonic activity. Understanding crust types is essential for studying geology and the Earth's structure.