What is cartilage? what is its role in the skeletal system?

Question 1 
car·ti·lagefirm, whitish, flexible connective tissue found in various forms in the larynx and respiratory tract, in structures such as the external ear, and in the articulating surfaces of joints. It is more widespread in the infant skeleton, being replaced by bone during growth.
a particular structure made of cartilage.

Question 2
The adult human skeletal system consists of 206 bones, as well as a network of tendons, ligaments and cartilage that connects them. Theskeletal system performs vital functions — support, movement, protection, blood cell production, calcium storage and endocrine regulation — that enable us to survive.