Osteoprogenitor cells are a type of stem cell found in the bone. They are essential for bone formation and repair, as they have the ability to differentiate into osteoblasts, which are the cells responsible for producing new bone tissue. These cells are primarily located in the periosteum and endosteum, the outer and inner layers of bone, respectively. When the body needs to heal or grow bone, osteoprogenitor cells become activated. They undergo a process of division and specialization, ultimately transforming into osteoblasts. This process is crucial for maintaining healthy bone density and structure throughout a person's life.