Caster

Well, now the use of Caster as a professional title is mostly due to the fact that different places have different magic folk, and some adventurers have a tendency to get a bit stabby when people are flippant with them.
"wizard, dont got one, cleric, none of them neither, sorcerer, not here, druid, well why didn't you say so, he lives in the grove of pine with the big willow tree, you passed it on your way into town." and next thing you know the helpful towns-person is getting stabbed and the possibility of the whole town going up in flames went from zero to significant.
So by just asking after the local Caster they can be pointed in the right direction immediately, and usually with less stabbing involved.

— Jasper Cameron, Leader of the Bronze Ravens

It really is a simple enough formula, go to a town, ask after the mayor or the local caster, find out what is troubling the area, or if there are any interesting locations, or if anything of not has happened recently, or if anyone saw the person or thing you are looking for.... Look, go to town, find important person, Ask about quest, Complete quest, get reward, repeat.
While the Mayor is expected to be more of an expert on interpersonal relationships in a town, the value of a Caster cannot be understated. The ability to quickly mend a broken piece of farm equipment or to heal even minor injuries can be a tipping point between a towns survival and its demise.
Casters also tend to know more about the surrounding lands, due to their frequent interactions with those that venture into them. Whether it is for a likely location to be successful on a hunt, the location of a lost herd of sheep, or early warning of an attack by monsters, bandits, or beasts, the knowledge they offer is invaluable to the town and often surprising useful to adventurers, who are (at least in their own opinion) more able and courageous than the caster in question.
I would caution any adventurers reading this that when dealing with a Caster it is often best to err on the side of caution, for while they may be a lowly hedge-witch, they could also be an archmage who likes the quiet life, or simply has family in the area. Alternatively they could be and ancient Emerald Dragon disguised as a human working on a research project beyond the comprehension of beings that only dwell on a single plane of existence, you just never know until you anger them.