Character archetypes are most succinctly defined as a preset of identifiable traits that neatly slot characters into categories with other, similar characters. Because the human brain loves categorizing things into neat boxes.
Do not be alarmed if your characters fit into notable character archetypes! There are literally hundreds of them depending on how specific you want to get with categorizing different character traits, and there are enough generalized archetypes that most if not all characters will fit into at least one box.
A few notable archetypes include: the Hero, the Mentor, the Lover, the Explorer, the Innocent, the Ruler, and the Outlaw.
For more details on character archetypes, check out the video below!