Magic Levels.
Muggle: A Muggle has its own type of magic, Adrenaline Magic, in a great deal of stress or extreme emotion, a Muggle has an adrenaline rush, in great stress this adrenaline will suck up ambient magic and the Muggle will be affected. Example: a Muggle women's child is trapped under a car, the stress and horror of the event send adrenaline into her blood stream that adrenaline sucks up ambient magic and the Muggle women does the impossible she lifts one end of a car up and pulls her child out, unless documented by witness most Muggle's don't notice or forget they did that great feat of physical power.
Squib: A child born of a magical family without any useable magic in them, they have latent magic so they can see things from the magical world like, Dementors, Phoenix's, Anti-Muggle wards don't work on them but it some times can confuse them or cause migraines, squibs have the ability to use Adrenaline Magic, they have also been known to have weak magical gifts.
Wizard/Witch: A witch or wizard has active power the use a foci or wand then they thinks of the things they want and vocalize it into an incantation, then the magical effect such as a levitation charm that makes an object float, a witch or wizard generally has a couple of magical gifts such as Apparition, Animagi, Metamorphamagus and generally have enough power to duel continuously using magic for half an hour.
Sorcerer/Sorceress: A Sorcerer or Sorceress generally is more powerful than a wizard as they can duel for about one hour and fifteen minutes of continuously magic casting, magical gifts are generally more numerous or more powerful, a sorcerer if trained can use Wandless magic up to around second to third year magic, most sorcerers have an inherent gift of mage sight but to use it you need constant training and usually needs another to train them, silent magic also is said to be easier.
Enchanter/Enchantress: A Enchanter or Enchantress is the same as a sorcerer but Enchanters have a lot more magic just to be able to be called an Enchanter, A Enchanter has a the gift of magical chant it allows the user to repeat a mantra and the effects happen depending on what you are enchanting or words said, Example: You could enchant a door way to turn a persons clothes into a clown suit every time they walk through it, this can also be achieved by magical runes, some Enchanters that are more powerful than normal can enchant metal, metal enchanting was mainly used back in the founders time to enchant weapons or swords like the Sword of Gryffindor, the other ability is to enchant bone to be able to enchant ritual tools or necromancy tools, then the last and the one that needs the most power is enchanting blood, this is powerful because of the link to blood magic and can be used to enchant a living person mainly used in the old days to make females more beautiful so they could get rich husbands.
Dark Enchanter/Dark Enchantress: A Dark Enchanter or Enchantress uses the power of Emotions but mainly negative ones to overpower enchantments to make explosions or to make the enchantments permanent or more deadly.
Elemental: A elemental uses the power of elementals such as: Fire, Water, Air, Earth these powers are above the power of sorcerer and a elemental can't use the powers of a enchanter they are on the same level, a elemental also if they are powerful enough can use a mixed gift these are: Larva (fire/earth), Ice (air/water), Metal (earth/water), Lightening (air/fire).
Multi-Elemental: A multi-elemental is a lot more powerful and they use more than one elemental at a time and can mixed to base elements (fire/water/air/earth) to get the mixed gifts as well. (Larva/ice/metal/lightening)
Magus: A magus has a magic core that can continuously fire magic at a high rate for 4 hours using a killing curse, a magus has a mage-sight, nearly always multi-Animagi and has heightened magical senses and can use Wandless magic at any level and power, and is said to be one of the best power houses of magic that can fight. Can also use either elemental powers or enchanting powers. Also said to have extended life up to 4 thousand years old.
Arch-Magus: An arch-magus has more power than a magus, but can also use both elements and enchanting. Up to 6 thousand years old.
Overlord: An Overlord can use all powers above and has a supreme amount of magic and is one of the most powerful beings on earth, they can use or have any magical gift they want and are said to be immortal.