So osteocides build bones, but osteoclasts do the opposite of building. They basically resorb our bone. They break down the extracellular matrix of the bone and they secrete that into the blood. For example, they can break down our hydroxy appetite and they can release the calcium, the phosphate, back into the blood. So osteoclasts are the cells responsible for resorbing bone and that basically means they break down bone and they break down the extracellular matrix and release the minerals such as calcium and phosphate into the blood. Now, at times that can actually be helpful because let's say our muscle cells require calcium to contract.