Cancellous bone, also known as spongy bone, is a type of bone tissue that has a porous and lattice-like structure. It is found at the ends of long bones, in the vertebrae, and in the interior of flat bones. Cancellous bone contains trabeculae, which are small, interconnected columns and plates that provide strength and support. This type of bone tissue is lightweight but strong, and it helps to reduce the weight of the skeleton while still maintaining its structural integrity.