The vertebra is the whole back bone.  The spine is made up of 7 cervical, 12 thoracic, and 5 lumbar vertebra.  These bones stack on top of each other like building blocks and form a joint in the front (the disc) and two joints in the back (the facets) at every level.  The vertebral body is the main part of the bone and is the most common area fractured (usually in the elderly or with severe trauma).