Wizard 

What makes a wizard different from an enchanter, a magician, a sorcerer, a thaumaturgist[?], etc.? Well, sorcerers are sometimes evil, "black magicians" (i.e., practitioners of black magic), but in general, not a lot, although fantasy authors and FRPGs might use the names with narrower meanings.

For example, Dungeons & Dragons Third Edition (D&D3E), distinguishes between sorcerers and wizards:

• "Sorcerers create magic the way poets create poems, with inborn talent honed by practice."
• "Wizards depend on intensive study to create their magic. ... For a wizard, magic isn't a talent but a deliberate rewarding art."

Another example: "The difference between a wizard and a sorcerer is comparable to that between, say, a lion and a tiger, but wizards are acutely status-conscious, and to them, it's more like the difference between a lion and a dead kitten." (Steve Pemberton, The Life & Times of Lucifer Jones)

Lyndon Hardy's Master of the Five Magics suggests ascending ranks of thaumaturgist, alchemist, magician, sorcerer, and wizard.

Famous wizards in folklore and fantasy fiction (sometimes both) include:

• Merlin - from Arthurian legends and their modern retellings.
• Gandalf and Saruman - from J. R. R. Tolkien's The Lord of the Rings - are called wizards, but are really supernatural entities.
• Elric of Melniboné - often called a sorcerer or a wizard - from Michael Moorcock's Elric of Melniboné and its sequels.
• Sparrowhawk[?] - from Ursula K. LeGuin's A Wizard of Earthsea and its sequels.
• Cugel[?] the Clever, Rhialto[?] the Marvelous, and others - from Jack Vance's Dying Earth stories.
• Rincewind[?] - strictly a "Wizzard" (it says so on his hat) and the wizards of Unseen University - from many of Terry Pratchett's Discworld novels.
• Elminster[?] - featured in many of the Forgotten Realms fantasy novels and RPGs.
• Belgarath[?] - created by David Eddings as a leading character for The Belgariad series of fantasy novels (also called 'Belgarath the Sorcerer').
• Michael Scot[?] - protagonist of Michael Scott Rohan[?]'s The Lord of Middle Air - a historical figure and an ancestor of the author!
• Harry Potter, Albus Dumbledore, Severus Snape, Lord Voldemort, and all other non-Muggle male characters from J. K. Rowling's Harry Potter and the Philosopher's Stone and its sequels. (The females are witches).
• Dr. Strange is a wizard superhero and Sorcerer Supreme in the Marvel Universe.
• The Wizard of Oz

The eponymous character of L. Frank Baum's The Wonderful Wizard of Oz is a fake wizard hiding behind stage effects.