On magical casters.
Classification of casters always have been troubling me so I will try to convey my idea here:
W I Z A R D S
Wizards are the type of MCs (Magical Casters) who are specializing on the usage of spells. See, the franchise of Haroldinho Le'Potterman (you know who I mean) is about wizards and this is a good example. Wizards have spells for cleaning the floor, for opening doors; Shortly saying, for every task. Usually they cast their spells verbally, making them very vulnerable to one very specific transmutation-modification encantation:
Erase Mouth.
M A G E S
Mages are the guys who can be called the magical artists. Sure, there are many Academical Mages, but usually it's the other way around. Mages don't use spells as their main weapon - their magic is in the freestyle, in using energies, summoning and transmutation in many creative ways with only their mind rather than spells which are somewhat like tools/lines of code. With this analogy, Mages are the programmers who write the code themselves while Wizards take from the code libraries.
Mages are not restricted regarded the usage of spells - they usually do, the only thing is that they might modify those spells easier. Instead of copy-pasting spells, they weave them themselves, adding modifications on the go.
D R U I D S
This is interesting. Druids as I believe don't directly use magic, at least not when it's causing disbalance. Druids are masters of natural magic, they sense it everywhere, in every living and unliving natural thing. Animals, plants, stones, water; Everything what is opposed to the Nurture is under Druids control.
They don't cast spells nor weave them. They just know "tricks". "Tricks" that will allow them to turn into animals, to command tree roots, to heal wounds. They unlock the nature part of their magical potential and just use those abilities as if they always could do that, as if they unlocked innate powers.
M O N K S
Monks are close to Druids in concept, but instead of unification with nature, they seek peace inside their souls.
A great monk unlocks their innate powers through discipline, high morals and inner peace. Think anyone from Kung-Fu Panda: they all have some sort of inner peace with themselves, and many are capable of inhumane feats, such as incredible fighting skills, chi stealing, paralysing or healing.
W A R L O C K S
Warlocks are sort of tricky. In my native language, they are called "dark(magic)book-ers", something like "users of dark magic who learn from dark magic books".
Their entire thing is they got their magic from a patron, a being of powerful nature that gifted them abilities of different kinds. They can learn to use the magical powers they were given as spells or incantations, but generally, these will just remain abilities. Think "opening unholy portals to hell so you can summon foul little demon minions" or "turn into a six-limbed monster cat with laser eyes" and such. Warlocks can lose their powers if they don't follow what their patron tells them to do, or can be punished by the patron severely, so much that their powers won't matter anymore afterwards.
P R I E S T S
Priests are too, like Warlocks, getting power from a patron in a religious fashion. It is tricky to differentiate of course, and even as I am writing this I am unsure how to tell the difference.
There is one, though. While Warlocks had their abilities are given by the patron and it is not necessary for them to have innate magical talents, Priests have their abilities unlocked by their patron. Meaning they cannot be taken away if the Priest loses faith or betrays their patron, instead gaining negative effects for using them since they use their religion as a channel, and boy oh boy if their deity doesn't have it turned on at all times.
Priests are somewhat religious Mages, not bound by specific spells.
C L E R I C S
Clerics are the religious Wizards type. They are reading their holy books and repeat prayers, wield powerful encantations and follow the guiding hand of their patron while doing so.
Their gifts aren't gifts exactly. They can be magically talented, but the only way they will use this talent is to cast standard and limited spells provided by their god. And, importantly, these words will not lose their power if they ever were to betray their patron. They will know the key to the patron's locker of magical powers, and the only thing the patron can do is either smile from the irony or try to weaken/block such spells.
P A L A D I N S
This... Is difficult. Yes, they are pretty much like Priests and Clerics, yet they are way more gifted than them. They are something like the middle ground between the religious duo and Warlocks: they are something like pawns evolved into chess queens, upgraded by their patron, given, not unlocked, strenght and powers.
They follow the orders of their god, and will be punished if they decide to turn away from them. They made their choice, and their patron would be qutie dissapointed once betrayed. The results may vary, but I think at least part of the powers will stay with the Paladin - at least the spells.
S H A M A N S
Shamans are too, quite quirky. But as I classificate them, I think they are somewhere in the middle between Druids and Warlocks.
Shamans are powerful masters of nature magic, but they are not bound to just that. They have a hint of Monks in them (spirituality), and usually have some sort of a patron (may it be a Spirit Animal or just any sort of spirit honestly). They can heal, they can harm; They can create, they can destroy - Shamans are not the keepers of balance, they are the keepers of the law of the jungle, of traditions, of history and myth.
S A G E
Sage isn't really a caster type of a magic user. A sage is just a person of experience and wisdom, who knows the secrets of life and destiny.
Sages don't make guilds. Many don't even think themselves as sages even. They are just people whose words have a weight to them. Ones who see and understand. They can learn magic, sure, of any kind at that, but they will always be something like a lowkey Monk: in peace with themselves, and wishing to help others.
S O R C E R E R
Sorcerers are the talent type casters. They have so much magic in them they can't control it.
This magical potential can be tamed yes, but with very hard training and maybe some limitations (think Shadow the Hedgehog's rings). Sorcerers don't know how to cast spells, but they have some skills and encantations that are weirdly specific or powerful. Some sorcerers are planetouched, and are gifted with powers over the elements (think benders from ATLA). Or they have wild magic in their veins, causing strange and random stuff to happen at times. Maybe they are capable of using just this one specific spell of gargantuan power which even the greatest magic casters can't replicate, or maybe they have some sort of superpower due to their gift (think Encanto or X-men).
B L O O D H U N T E R S
This is the trickiest one. Basically, think self-corruption for a greater good. It's like a Warlock, but usually without a patron. It is somewhat Sorcerer, but their innate potential is mixed with training and education of a Mage or Wizard.
In my opinion, Geralt of Rivia is one very clean example of a bloodhunter. Has innate potential (seventh son of a seventh son), has training (in Kaer Morhen), was "corrupted" (witcher elixir) and fights for a greater good. He is somewhat "evil", "dark" or "grim", but more in an antihero sort of way.
A R T I F I C E R S
Artificers are not exactly magic users. Their powers are granted not through patrons, not through training but through artifacts. It might be a badass sword (King Arthur?) enchanted armour (Ironman?) or pretty much everything.
Sad thing about Artificers is that without their artifacts, they are pretty much nothing. I say "pretty much" because to me, they are still a threat. Artificers are not just users of artifacts - they can be their creators. For this they will need some magic components, sure, but as such, they are to be feared in any situation.
Basically they are not-quite magically gifted people who study magic and it's physical implementations, such as runecircles and sigils, enchantments, alchemy and many more.
(Pictured: an artificer when threatened in their natural habitat)
S T A G E M A S T E R S
Even though Houdini wasn't a magic user, he was considered unnatural and mystical. A stage performer, an illusionist; Those people's magic is in the secret, in the way they trick people into thinkin they actually have magical powers while using nothing but tech.
I mentioned them just for a good measure, to illustrate what they basically are. They are sort of Artificiers, sort of Thiefs (regarding their sleight of hand) but almost never true mages. There could be a trope where a stagemaster is actually a magical caster of sorts, but it only adds an additional level of mystery. How do you make magic look like mundanity looking like magic?
Of course I will stay silent about the "battle-" modification for classes; A battlemage is a mage specifying in fighting, Battlewizard might know a couple of harmful spells to aid in battle (making them slightly similar to Bloodhunters but without the corruption bit). Generally any sort of battlecaster is just capable of using their magic quicker and on the go while in battle. Hop - and the enemy is petrified, turned to pebbles by a smash of a hammer seconds later; Shazam - and a trench instantly forms before your feet, swallowing a line of the incoming enemies and giving you the high ground advantage (*cue to Obi-Wan heavy breathing*).
Now we are done! I think I touched every matter, so please let me know if I forgot something; It might be that some classes are just variations of the already listed ones of course.
And so, I can show you the several criteria of classes classification:
-> Source of power.
-> Way of using said power.
And that's basically it. You can get your power from innate talents, unlocked sources of energy inside of you, from a patron, artifacts or some sort of mutation (Witcher elixirs).
The way you use it of course is different too. You can read spells out loud or can weave your own incantations, aka Bookworm versus Freestyler.
Sorry for a long post and here's a sweet potato: