According to Merriam-Webster, the definition of courage is
mental or moral strength to venture, persevere, and withstand danger, fear, or difficult.
While one typically hates to use dictionary definitions to define terms, one can certainly agree that this definition encompasses the meaning of the word very appropriately.
There are many characters in literature who must possess courage.
1. Katniss, in The Hunger Games, must possess courage so that she can both win the games and fight against the oppression of District One.
2. Steve Harmon, in Monster, must possess courage in order to make it through his trial (he is being charged with murder). He must be able to mentally stay strong and face the stereotypical mindsets of those who are sitting on the jury.
3. Miranda, in Speak, must be able to stay strong enough to face the conflicts she faces given her rape and alienation by her friends.
Outside of literary examples, I would say that soldiers, parents, teachers, and children all possess courage.