Cinder blocks, also known as concrete masonry units (CMUs), are rectangular blocks made from a mixture of cement, water, and aggregates like sand or gravel. They are lightweight compared to traditional concrete blocks, making them easier to handle and transport. Cinder blocks are commonly used in construction for building walls, foundations, and other structures due to their durability and strength. These blocks typically have hollow cores, which can improve insulation and reduce weight. Cinder blocks are often used in both residential and commercial projects, providing a cost-effective solution for various building needs. Their versatility allows for creative designs and applications in landscaping and outdoor projects as well.