Wizards, sorcerers, warlocks, shaman, and druids.

Wizards: wizards are normal spellcasters, they have mana, speak incantations and usually have, but do no need, spellbooks. Wizards, from the Old Common word Wisehard meaning "Wise being, or wise person". Wizards are natural*, they are born with mana, they link their powers to, long ago, when the first fey came into the natural world, magic spread into the world and among the mortal races, and the first spellcasters were made, then after the Binding of Magic, there were only wizards, but when a certain family has a long line of wizards, a sorcerer is born.

Sorcerers: as stated above, sorcerers are the descendants of long line of wizards, and perhaps some fey blood as well. Sorcerers have no need to study words of power like wizards, magic flows naturally for them, they tend to have larger mana pools, but they also have a smaller spectrum of spells. Sorcerers have magic flowing in their veins, which makes them unique among all spellcasters, hence the name, sorcerer, from Draconic "Sorc" translates into "source", then "-ier", or "-er".

Warlocks: are strange, shady spellcasters, who draw power from dark, sinister sources. Warlocks are often mistaken as male witches, but this is not the case, witches and warlocks are the similar, though witch is more of a sub-race of men. It is unknown whether warlocks are natural or learned spellcasters, learned meaning that anyone can become warlocks, but it is known how they get their eldritch powers, through sigils and rites they contact devils and other powerful entities and make a dark pact with them, an outward sign of this pact is called a "witch mark", which can range from a freckle to a scar, to a birthmark. Since they practice dark magic, warlocks and witches are most often burned at the stake, for fear of their demonic powers. Warlock comes from the Old Common word "Wurrlok". meaning "heathen, or traitor".

Shaman: are a type of primal learned spellcasters who call upon nature spirits to gain spells. Shamanism is a slightly mysterious form of magic, the method is thus; first you carve totems or make tiki amulets, as a focus to contact ancestral spirits, then they take advice and spells from the spirit. They are also known for making astral journeys into the Astral or Ether Realms, coming back as a spirit callers. "Shaman" comes from the orc word "Shkrog", or "Shkrogan", which means "spirit seer".

Druids: druids are learned spellcasters who embody nature and animals. The process to becoming a druid is called the Rite of Green, first you must ask the Green One, or Nature, to take you as a disciple, then after proving yourself worthy, he bestows you with a mana pool, so druids are natural yet learned, and a strong link with nature and the Green One. Druids protect forests, rivers, and other areas of natural beauty, similar to dryads, and can sometimes, mislead lumberjacks and others like them.

Note: Magician, or mage, is a neutral term that refers to all spellcasters, though it is usually used to mean wizards or sorcerers.

*Natural and learned, natural means either being born with, or having a mana pool, while learned spellcasters do not have mana pools, but use other means to cast spells.