According to Einstein's famous equation E = MC2, or Energy = Mass times the speed of light times the speed of light. This tells us that anything that has mass, such as matter, is comprised entirely of energy. Any physical object with mass is therefore simply a lump of energy existing in some stable form.

As I understand it, all forms of energy, including chemical energy, kinetic energy and potential energy are covered by Einstein's equation, meaning that fundamentally all forms of energy are the same basic 'stuff' (for want of a better word). My question is, therefore, what exactly is energy? I want to get to a fundamental understanding of energy, because it seems that such an understanding would help to explain much of reality.

I'm not asking for explanations about work done etc, I'm asking at the fundamental level what is energy?

An electron is both a particle and a wave, and we cannot define exactly where a subatomic particle/wave is because it is spread out across time and space - we can only define it through probabilities. Wouldn't there need to be infinite precision and no uncertainty in nature for nature to be deterministic? Considering that infinite precision and certainty don't appear to exist - because experiments show randomness and uncertainty exists at the heart of nature, then would it be correct to assume that both atomic and subatomic particles/waves do not always interact with one another with infinite precision and if so then is it correct to conclude that nature cannot be deterministic - i.e. by having exact knowledge of the starting conditions of the universe and infinite computing power it would still be impossible to calculate exactly how the universe would evolve?