Slabs are flat, thick pieces of material, often made from concrete, stone, or metal. They are commonly used in construction for floors, sidewalks, and foundations. The size and thickness of a slab can vary depending on its intended use, providing stability and support for structures. In geology, slabs can refer to large, flat sections of the Earth's crust, such as tectonic plates. These plates float on the semi-fluid layer of the mantle and can move, causing earthquakes and volcanic activity. Understanding these slabs is essential for studying earthquakes and plate tectonics.