Tulang Keras is the Indonesian term for "hard bone," which refers to the dense and strong type of bone tissue found in the human skeleton. This type of bone provides structural support, protects vital organs, and facilitates movement by serving as attachment points for muscles. The composition of tulang keras includes minerals like calcium and phosphorus, which contribute to its strength and rigidity. It contrasts with tulang lunak or "soft bone," which is more flexible and found in areas like the ends of long bones and in the vertebrae. Understanding the properties of tulang keras is essential for fields like medicine and orthopedics.