Shear walls are vertical structural elements designed to resist lateral forces, such as those caused by wind or earthquakes. They are typically made of reinforced concrete or masonry and help maintain the stability of a building by transferring these forces down to the foundation. These walls are strategically placed within a building's layout to enhance its overall strength and rigidity. By providing additional support, shear walls help prevent excessive swaying and potential structural failure, making them essential in the design of tall buildings and structures in seismic zones.