In The Wonderful Wizard of Oz, the existence of witches is quickly established as Dorothy discovers she killed a Wicked Witch with her house and finds herself greeted by a self-identified Good Witch. Later, Dorothy is sent to destroy the Wicked Witch of the West, and in the final act of the story, undertakes a journey to find another Good Witch, Glinda.
Except, in later books, Glinda is not called a witch, but a sorceress.
"Well," fans might think, "they're just different terms for women who use magic, right?"
Well... Maybe not.
I was going to tackle this topic in an Oz story, but have decided to skip it and just tell a story.
In one of the notes in The Annotated Wizard of Oz, Michael Patrick Hearn points out that witches traditionally work for Satan, while sorceresses work for themselves. However, while Baum states in Wonderful Wizard that there is a power of Good and a power of Evil in his fantasy world, it does not appear he intended there to be a Devil.
The way Evil (or wickedness) comes about in Baum's world is that people "do not try to be good," or rather, as I've observed, that villains follow their selfish, self-serving goals rather than goals that will actually help people. That is what makes Wicked Witches different from any Good Witches. Good Witches work for the good of their people or the entire Land of Oz.
Okay, but what's the difference between witches and sorceresses?
In The Wonderful Wizard of Oz, we have two witches who use magic that we as the reader observe: the Good Witch of the North and the Wicked Witch of the West. We are only told they work magic or use a little chant before they turn their hat into a slate or make a bar of iron invisible. Nowhere are we told that they use tools, herbs, or extensive magic words to work their magic. Thus, it seems they actually have magic power.
In contrast is Glinda. A fun fact check is that nowhere in the first four Oz books does Glinda work magic. In The Marvelous Land of Oz, she uses magic tools, but these items are already magical and would presumably work for anyone who knew how to use them. She gives advice on how to use magic devices in Wizard and Ozma of Oz, but is absent in Dorothy and the Wizard in Oz. In The Road to Oz, we are told she makes a tree grow and bear fruit in a very short time, then makes it disappear. Baum does not tell us if she used tools or just made it happen. A similar case is in The Emerald City of Oz when she reveals she's created an invisible barrier around Oz, but we are not told how she accomplished this. Once again in Tik-Tok of Oz, we are told Glinda performs a "magical ceremony," but what this consists of, we have no idea.
The biggest revelations about Glinda's way of working magic happen in The Lost Princess of Oz and Glinda of Oz. When Ugu steals Glinda's magic tools, she is unable to work magic. Furthermore, she must use tools to try to save Dorothy and Ozma in the latter book. Thus, it seems, Glinda does not have magic power of her own, but she knows how to use magic tools and magic words to accomplish great feats.
I must also point out that Baum says that Mombi is only a sorceress (or "wizardess") in The Marvelous Land of Oz. However, he later states that she was the Wicked Witch of the North in Dorothy and the Wizard in Oz. This must mean that magic power can be stripped from a witch, presumably turning them into an otherwise harmless woman. (Mombi, we must assume, has learned every bit of magic she could find, so even without magic power, she's still capable of quite a lot.)
So, how do Witches get magic power? According to many old legends, they sacrifice youth and beauty for their wicked arts. I came up with another concept: they can turn in their names for magic power, which is why the Wicked Witches disposed of in The Wonderful Wizard of Oz had no names. (As far as Baum's writing is concerned.) The thing is, it's a bit more than becoming a nameless person. Giving up your name is beginning to give up your identity, and in the Wicked Witches' cases, their main concerns were becoming more powerful and holding dominion over their people.
So wait, what about the Good Witch of the North? According to Thompson, she is Queen Orin who Mombi had tried to transform into a Wicked Witch, but since Good is greater than Evil, Orin could not be turned into a Wicked Witch, and so became a Good Witch.
But as I'm not a fan of the Good Witch of the North being disposed of, I've come up with another suggestion, in that rather than sacrificing youth, beauty or identity, the Good Witch of the North was given her powers as a reward for previous selfless acts and tasked to help protect the people of Oz from her base in the Gillikin Country. She is not a fairy, but not a sorceress as she doesn't use tools, so the term "Witch" is closest to what she is, so she took it, identifying as a good witch. (The Good Witch of the North will be making a return in a short story I've written, keep your eyes open.)
Glinda is often mistakenly called a Good Witch, although she's actually just a sorceress, but she's not particular as long as people remember she's Good and on their side.
So, why do Mombi and Singra (the Wicked Witch of the South in Rachel Cosgrove Payes' The Wicked Witch of Oz) have their names? Perhaps these are aliases or they recognized the danger of losing their identities and decided not to go that far.