Concrete block, also known as concrete masonry unit (CMU), is a building material made from a mixture of cement, water, and aggregates like sand or gravel. These blocks are typically rectangular and come in various sizes, making them versatile for construction projects. They are commonly used for walls, foundations, and other structural elements due to their strength and durability. Concrete blocks are favored for their fire resistance and sound insulation properties. They can be easily stacked and mortared together, allowing for efficient construction. Additionally, they can be finished with various materials, such as stucco or paint, to enhance their appearance and weather resistance.