Heroism is the quality of acting with courage and self-sacrifice, especially when facing danger or difficulty to help others. When firefighters rush into a burning building to rescue people trapped inside, they're displaying heroism. When a bystander dives into a freezing river to save someone from drowning, that's an act of heroism.

True heroism often involves putting someone else's safety or wellbeing ahead of your own. During World War II, soldiers stormed beaches under heavy fire to defend freedom. Everyday heroes show heroism too: a student who stands up to a bully threatening someone weaker, a nurse who works through exhaustion during a medical crisis, or a person who tells the truth even when lying would be easier and safer.

Heroism differs from simple bravery because it centers on sacrifice for others. You might bravely ride a roller coaster or try out for a play, but heroism means doing something difficult or risky to help someone else, while personal challenges fall into the category of courage or bravery.

Today we recognize that heroism appears in many contexts beyond battlefields or emergencies. A whistleblower who exposes corruption at great personal cost, a teacher who fights for a struggling student, or a scientist who dedicates decades to solving a disease all demonstrate different forms of heroism.