Manaism (mana-ism) is the belief that spells can be “powered” by discrete units of spellpower called mana. The idea has given rise to many types of mana, depending on how it is obtained, as various means can be used to generate mana, each a result of their own version of manaism:
Personal manaism holds that a person generates mana within themselves, and can use that to power their spells.
Aer manaism holds that mana can be gradually collected from the mana in the aer.
Natural manaism holds that mana can be harvested from all living beings
Necrotic manaism holds that mana can be harvested from the dead
Material manaism holds that mana can be extracted from materials, most often crystals (primarily quartz).
Extraplanar manaism holds that mana can be used to drill a hole into a “plane of mana” from which mana may be siphoned.
However, not all methods are ascribed the same amount of mana. In particular, personal manaism is believed to be the least efficient, and so within the monetary manaism regime, the contribution of mana generated from each individual is considered very minor. Note that many methods use mana to beget more mana, and of these their efficiency may not be the same.
Mana can also be created directly with spells / various other means, but the methods that are not well known are not likely to be as successful, and generally cannot result in the production of a tremendous amount of mana.