Matter is the “stuff” of the universe — the atoms, molecules and ions that make up all physical substances. Matter is anything that has mass and takes up space. Energy is the capacity to cause change. Energy cannot be created or destroyed; it can only be conserved and converted from one form to another.
Consequently, is energy is matter?
The mass of these three particles is less than the mass of a neutron, so they each get some energy as well. So energy and matter are really the same thing. Completely interchangeable. And finally, Although energy and mass are related through special relativity, mass and space are related through general relativity.
Why is energy not a form of matter?
It would seem that photons would be matter whereas the waves wouldn't. It turns out that for both theories light isn't matter. A photon is not matter because it has no mass. This is different from matter such as electrons and neutrons which have masses.