The umbilicus or your navel (belly button) lies on the <em><u>stomach </u></em>while the sternum or the breast bone lies in the anterior your <em><u>chest.</u></em>
The <u>umbilicus</u> or more commonly known as navel is used to refer to the vestige which is left after the umbilical cord is cut off when the baby is born.
The <u>sternum</u> or the breast bone is the bone which along with your ribs help to protect your internal organs like the heart, lungs & other blood vessels & capillaries.