Endochondral ossification is a biological process where bone tissue is formed from a cartilage template. This process is crucial during the development of long bones, such as those in the arms and legs. Initially, a cartilage model is created, which is gradually replaced by bone as the organism grows. During endochondral ossification, cells called chondrocytes produce cartilage, which is later transformed into bone by osteoblasts. This process is essential for the proper growth and development of the skeletal system, allowing for the formation of strong and functional bones in mammals, including humans.