Cortical bone, also known as compact bone, is the dense outer layer of bone that provides strength and support. It forms the hard exterior of bones and is crucial for protecting the inner structures, such as the bone marrow. This type of bone is organized into tightly packed structures called osteons, which help in maintaining its strength and durability. Cortical bone makes up about 80% of the total bone mass in the human body. It plays a vital role in weight-bearing and movement, allowing the skeleton to withstand various forces. Its dense nature also aids in the storage of minerals, such as calcium and phosphorus, essential for overall health.