All bone types consist of compact bone and spongy bone.
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Selected terminology:
Periosteum – double-layered membrane that lines the external surface of a bone.
Endosteum –membrane that covers inner canals of compact bone and trabeculae of spongy bone.
Osteoprogenitor cells – highly mitotic stem cells; originate in periosteum and enosteum.
Osteoblasts – bone-forming cells.
Osteocytes – mature osteoblasts.
Osteoclasts – bone-destroying cells.

A structural unit of a compact bone is called an osteon (or Haversian system ).
Osteon – cylindrical structure oriented parallel to bone's long axis.
Osteon consists of hollow tubes, one inside the other, called lamella .
Compact bone is sometimes called lamellar bone .
In the center of each osteon there is a Haverisan (also, central ) canal that contains small blood vessels, nerves and, sometimes, lymphatic vessels.

Haversian canals are connected to each other by Volkmann's (also, perforating ) canals with their perforating blood vessels and nerves.
Volkmann's canals are oriented along the short axis of the bone.
Lacunae – small hollow spaces between lamellae. Each neighboring lacuna is connected by canaliculi
– hairlike passages that form a network of tiny canals.
Osteocytes – spider-shaped, mature bone cells that occupy lamellae. Through the canaliculi, all osteocytes in osteon are connected with each other and with the Harversian canal.
Functions of an osteocyte :
--to maintain the bone matrix;
--to act as a strain and stress sensors when the bone is subjected to excessive, damaging stimuli.
Interstitial lamellae – layers of bone matrix between osteons.
Circumferential lamellae – layers of bone matrix that surround osteons.

Spongy bone is the structure located deep in compact bone. It is made up of thin trabeculae that align along the stress lines. This helps the bone to resist stress while maintaining its light weight.
There are no osteons present in spongy bone; however, its trabeculae contain lamellae, lacunae interconnected by canaliculi, and osteocytes.