Back with another Lore question! How do spells work from a mechanical perspective? I understand where magicka comes from, that's not the issue.

How "flexible" are spells? Do people learn individual spells that produce a known set of effects and just repeat those? Or would do they learn the use of an element or effect (fire, for example) and are then able to manipulate it as they see fit? Somewhere in between?

In other words, is it more appropriate to say that a mage learns to cast a fireball or that a mage masters fire and can bend it to his will? Is it more about memorization or willpower?

Additionally, what kinds of limitations might there be on the way people can cast spells? What stops me from just creating an explosion on top of you? In the games the projectile typically originates from the caster, which makes sense for destruction spells, but does that apply to mind affecting spells? Can you dodge a spell like that? Why does it need a projectile if the target is a mind?

I could go on for a while. I guess the point is, when we shed the limitations of gameplay mechanics and focus on the Lore, how does magic function from a practical standpoint?