Bones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. This chapter briefly covers a wide spectrum of areas related to elementary bone pathophysiological features and basic bone research. While bone embryology, osteogenesis, bone remodeling, bone development, osteoblast and osteoclast biology constitute the main contents, topics important to the understanding of bone metabolic diseases are also reviewed. The significance of bone enhancing factors and effect of immune system on bone is discussed. Elementary knowledge is also given for the relation of bone and implants.