The hard outer layer of a bone is called compact bone while the interior of bone is soft and porous. It is called spongy bone. Spongy bone contains blood vessels and bone marrow.
Like cartilage, the matrix of bones also contains collagen. But it also contains minerals e.g. calcium and phosphate. We know that cartilage contains a single type of cell. On the other hand, bones contain different types of cell. The mature bone cells are called osteocytes.