Ans: Ossification definition is as follows, it is the process by which the formation of bone occurs. There are two types through which the formation of the bones takes place:Intramembranous Ossification: In this process, the spongy bone is developed directly from the sheets that are made of undifferentiated mesenchymal tissue.Endochondral Ossification: The bone is developed by replacing it with hyaline cartilage. In this case, bone is not developed directly, instead it is a template for the new bone.