**Cement** is a finely ground powder made from a mixture of limestone, clay, shells, and silica. When mixed with water, it forms a paste that hardens over time and binds materials together, creating a solid structure. Cement is a key ingredient in making concrete, mortar, and grout, and is widely used in construction for building foundations, roads, bridges, and other infrastructure. There are different types of cement, including **Portland cement** (the most common type used in construction), **white cement**, and **rapid-setting cement**, each designed for specific applications and conditions. Cement's ability to harden and gain strength over time makes it a fundamental material in the construction industry.