What is the definition or description of: heel spur?

See below: A true heel spur is the projection of bone from the main body of the calcaneous (heel bone).

Calcium deposit : A heel spur results from chronic plantar fasciits, or a pulling of the plantar fascia at its attachment to the heel bone. It is a calcium deposit that results from the constant pulling. It does not need to be removed in order to relieve the heel pain.

Bony prominence.: A heel spur is a bony prominence that can develop at a site of increased tension where the plantar fascia originates from on the bottom of the foot or where the achilles tendon inserts into at the back of the heel.