Immature bone cells are called osteocytes but after they are fully matured, they are referred to as osteoblasts.
Actually, it's the other way around. Immature bone cells are known as osteoblasts, and once they become fully mature and surrounded by bone matrix, they are referred to as osteocytes.
Osteoblasts are responsible for the formation and mineralization of bone. They synthesize and secrete proteins and other components of the bone matrix. As they deposit new bone, osteoblasts become embedded within the mineralized matrix and differentiate into osteocytes.
Osteocytes are the primary cells found in mature bone tissue. They maintain and regulate bone health by sensing mechanical stress and coordinating remodeling processes. Osteocytes have numerous extensions or processes that extend through tiny canals called osteocytic lacunae. These processes allow them to communicate with neighboring osteocytes, osteoblasts, and osteoclasts, playing vital roles in bone remodeling and maintaining bone homeostasis.