Everything is made up of nebulae. Without it, the world would cease to exist. Nebulae are drawn from the stars--and more generally, from constellations.
Below are the twelve main nebulae.
Humans each use two of the base nebulae--a major and a minor. Their major is often based on their sun sign, as there's a higher concentration of a certain nebula in the air each month, which feeds into their nebulae receptors. Their minor is developed in much the same way, but that's typically based on the second highest concentration of nebulae around their birth, which correlates to their moon sign. Those two, they can control at will. For all other nebulae, they need to use formal spells to control them.
There are still many more nebulae--sub-nebulae. Most fall under one or multiple of the twelve base nebulae and have functions such as 'speed,' 'invisibility,' and 'magnetism.' All twelve nebulae combined create the Andromeda sub-nebulae, which are neutral in power. Andromeda itself takes an extremely high concentration of all nebulae and is the nebula of 'creation,' and its opposite, Norma, takes the same amount of power for the nebula of 'void.'