Heroes: Definition Of An American Hero

Americas Heroes
The first thing I would like to say is the definition of a hero "Someone who behaves selflessly, usually at considerable personal risk and sacrifice, to comfort or empower others and to make the world a better place." The reason that I am writing about this is that it has been brought to my attention about military personnel, firefighters, and police officers being considered hero’s.
One of the main reasons that they are viewed as heroes is that all of the jobs that they participate in are life and death at times. They are willing to go into the face of danger and to fight through the adversity. This makes people as being brave with is one of the characteristics of a hero.
Another leading idea to why they are considered heroes