There are many different tropes of stock characters in literature. I briefly talked about the fool in an earlier post. Other commonly known ones are the hero (or anti-hero), the villain, the mentor, the foil (the opposite of the main character, like Cinderella is made more beautiful because her stepsisters are ugly), the girl next door, bad boy, etc.
I am not fond of stock characters simply because authors think that once they have a position for each character there is not need for more development. However, for beginning writers these characters are a perfect starting place for understanding character and the vast difference between people. Even characters that fall into the same “stock character” are vastly different.
Take the tragic hero, for example. A tragic hero, in essence, is one who illicits sympathy from the audience. Two examples I will choose are Hamlet from, well, Hamlet, and Anakin Skywalker from the Star Wars franchise. Both are considered tragic heroes, though they are very different in themselves. Both are vengeful, but the former is careful and the latter is hotheaded. We are on Hamlet’s side to avenge his father’s death, but we feel anger at Anakin’s rash hatred. In the end, though both die peacefully (Anakin having saved his son and Hamlet killing his uncle), Hamlet is indeed a more honorable person, whereas Skywalker is more of a villain.
Taking these two examples, it is easy to say that one stock character can be interpreted very differently by different authors. So, in developing characters, start off with a character trope, but build off it.