Light Energy is the governing force behind all that exists within the Lightverse.
It has famously been known under three different names throughout history:
It originates from The Light Realm and creates new bubbleverses when it seeps through to the Deep Void. It does not have a physical form and could be described as the code programming the laws of the universe. The Six original Gods are said to be made of pure Light Energy. Whether or not this applies to the other Gods is debatable as they, like mortals, were a byproduct of The Goddess of Creation's eternal sleep.
When Light Energy breaks free from the Light Realm, it is known to sometimes take on a personality and form of its own. This culminates in them becoming the first God of their respective Bubbleverse, although this wasn't the case with our Multiverse. [See The First God]
Magic occurs when a person learns to reprogram the world around them in various forms. Things like creating fireballs and stopping time are both theoretically the same power being used in different ways. This is also what allows subject 417 to copy the powers of others. Mortals' use of magic is theorised to, in part, be due to the influence of Echoes.
Powerful items like Gascoin's Hat are able to negate the powers of Light Energy.