Intrigued and fascinated by mythology, author Joseph Campbell studied the myths of many cultures. He claimed that nearly all myths, and some other story types, have similar ideas, and the heroes’ adventures are almost identical in their format; they’re just told from different characters’ points of view in diverse plots.
He called the twelve stages of adventure the ‘hero's journey.’
1. Ordinary World: This step refers to the hero's normal life at the start of the story, before the adventure begins.
2. Call to Adventure: The hero is faced with something that makes him begin his adventure. This might be a problem or a challenge he needs to overcome.
3. Refusal of the Call: The hero attempts to refuse the adventure because he is afraid.
4. Meeting with the Mentor: The hero encounters someone who can give him advice and ready him for the journey ahead.
5. Crossing the First Threshold: The hero leaves his ordinary world for the first time and crosses the threshold into adventure.
6. Tests, Allies, Enemies: The hero learns the rules of his new world. During this time, he endures tests of strength and will, meets friends, and comes face to face with foes.
7. Approach: Setbacks occur, sometimes causing the hero to try a new approach or adopt new ideas.
8. Ordeal: The hero experiences a major hurdle or obstacle, such as a life or death crisis.
9. Reward: After surviving death, the hero earns his reward or accomplishes his goal.
10. The Road Back: The hero begins his journey back to his ordinary life.
11. Resurrection Hero: The hero faces a final test where everything is at stake and he must use everything he has learned.
12. Return with Elixir: The hero brings his knowledge or the "elixir" back to the ordinary world, where he applies it to help all who remain there.
A quick internet search will also give you a visual reference that shows you the stages in diagrams.
Find more on Story Structures.