According to me, courage is present in everyone but only a few make the effort to pluck up this courage and too often choose the easiest way to handle a situation. Situations that needs strenghtness (phisically or mentally) occur every day, when you need to study for a difficult exam or even when you have to wake up to go to school. However this is not courage, what we are speaking about is linked with serious situations and sometimes extreme danger.
When I am thinking about courage, the first example that comes up to me is people who are fighting their illness. When people face a despondent diagnosis people have generally two options: or to be resilient and fight back or to fall into a deep depression. It takes courage to keep your mood up even if you know that your state of mind is essential in your treatment.
As far as I am concerned, I don't know if I would have the guts to face such kind of situations but sometimes it is a person's duty to have some. If you are witness of an attempt to harsh a people's health it is your duty to react as prompt and hard as you can.
Finally I had like to give an exhaustive list of people that have shown courage in acting for their convictions: Gandhi, Martin Luther King, Nelson Mandela, Benazir Bhutto but also artists like Johnny Clegg and many others. Those are the one why the word courage exists.