If it has any resemblance to D&D it would be more in the matter of subtyping than the schools. It's much rarer for someone to focus on spells just to protect themselves (e.g. an Abjuration specialist) over learning everything they can about the manipulation of rocks. Since a component of spellcasting is understanding what you're trying to [i]do[/i], it's much easier to e.g. learn a bunch of fire spells and transfer that into learning more about fire etc. etc. But since that's not the entirety of it you can [i]also[/i] go the hermetic route and just learn a lot of spells in detail--though unless you're a master of manipulating mana itself you'd be one of those types either using lots of weak spells or constantly going through the full chant. Corinne is a fun example, because she's technically the first type (specialised on fire and lightning) but hasn't got the wealth of experience with it to cut down the spellcasting to quick times yet (working like the latter). 

Though there are some processes so enormously complicated that once you start pulling in prepared ingredients and enchantments to actually do something more complicated than your average transient effect (e.g. becoming a lich) then you're right into full ritual preparation.

And someone with a ridiculous amount of mana and enough willpower can more or less learn magic by [i]making[/i] it happen. But that's an edge case and anyone that wanted to keep that up for any length of time would need some way to regenerate mana [i]very[/i] quickly on top of raw reserves, so that's more a thing that tends to be well... monsters and the like.