This article is how I picture the nature of mana and magic.
What is mana
Mana is a usually invisible energy. It exists in three forms: Free mana energy which flows through the world and forms a homogeneous force field, sentient mana - or souls - which inhabite living creatures, or manifested mana which appears in form of elemental energy. All three forms can be converted into each other.
Mana as liveforce
When a new living being is born, free mana around it flows into the new body, possesses it, becomes sentient and becomes the soul of the creature. The soul which possesses the body is not aware that it is mana energy but rather thinks it is the creature itself.
When the being dies the mana leaves its body, scatters, loses its sentience and is absorbed into the free mana again.
Mana as magic
Living beings, or rather the sentient mana concentrations which believe that they are living beings, have the ability to shape free mana energy around it with the power of their minds. Beings do not possess this ability intuitively but rather have to learn it. When the being has learned how to control free mana energy its intelligence allows it to collect mana energy around it and its willpower allows it to release it in form of destructive or constructive magic to shape the world around it.
Destructive magic
When a living being utilizes mana energy as a destructive force, e.g. casts an attack spell, it creates an illusion of one of the 8 Elements. The illusion itself does not create any damage - it is the willpower of the spellcaster which manifests itself in form of the illusion which does. For that reason a dose of water can have the same destructive force as a ball of fire and any projectiles generated by magic will immediately disapper after damage has been done (unless the spellcaster utilizes additional mana to keep these illusions alive for a while).
Healing magic
Mana can also be channeled for more constructive purposes. One of these purposes is healing magic. When mana is used for healing the spellcaster basically transfers free mana energy to the soul of another living being or himself which can then be used to rapidly repair the body or the mind of the being.
Enchanting magic
Another constructive use of mana is by "programming" mana and then infusing items with it. This can give items all kinds of magic properties. Weapons can be enchanted to leak elemental mana energy when they are swung so that they inflict additional magic damage. Armors can be enchanted to disturb others and focus the same element they have been enchanted with.
Unfortunately these effects aren't permanent because the mana will leak out of the item over time.
Summoning magic
Advanced magic users can even control mana so good that they can concentrate it until it forms a new sentience. These sentiences can either be manifestations of mana without a physical body or can be created inside an inanimate object which then comes to live. The first beings are called "Elementals", the latter beings "Golems".
