I have a problem about , "what is the real meaning of piramids to the Egyptian culture?

I have a problem about , "what is the real meaning of piramids to the Egyptian culture?
After the ruler died (or other prominent royal figures like queens), their bodies were wrapped and preserved as a mummy, and placed in the Pyramid. (source (http://www.travelandtourisminfo.com/Egypt/Pyramids-of-Egypt-Great-Pyramid.asp))