According to many observations finding that all components of the universe are about 68% of dark energy, 27% of dark matter and 5% of ordinary matter. What is these percentages representing for? Is this the energy density percentage? Since dark energy is an energy, but dark matter and other matter are "matter" components not "energy", so I do not get it why we can include all of them even they are not the same quantity. (If I misunderstand something, please let me know)