Witches
There is a common misconception that witches are merely a human that has gained magical powers either through hereditary means or through contract with a god or other powerful being (though you could contract with a fairy in your garden should you fancy it). There certainly are witches that gain power from others and even humans who do so, but there is a biological difference to witches. That lies in the specialized glands in the palms of witches termed the magicaiferous [magic-bearing] glands. Should you happen to meet a true witch, you may not that the palms are similar to a human's save for a fine coating of light hair (or slight stubble depending on the grooming habits of said witch). These particular glands produce a sort of sweat-like substance that appears to contain magical properties similar to the alchemist's powder base you can find in any potion worth its salt. Along with aesthetic choices, wands and staffs serve a purpose in magic for witches, serving as a collecting surface or even collecting container for the magic produced from the palms. Noticeable are the stylized orbs at the tops of staffs. With true witches, you can see that a fluid has collected within the top of the staff with the witch can draw upon for more powerful spells or in emergencies.