A commander is a person who leads and gives orders to a group, especially in the military. When soldiers receive instructions from their commander, they're expected to follow those orders because the commander is responsible for the group's success and safety. A ship's commander decides where the vessel goes and how the crew operates. An army commander plans battles and directs troops.

In the military, different ranks of commanders exist: a battalion commander leads hundreds of soldiers, while a company commander leads a smaller group. The commander-in-chief is the highest military authority, and in the United States, that's the President.

Outside the military, people sometimes use commander more loosely. A teacher might jokingly say a bossy student is trying to command the classroom, or kids might pretend one of them is the commander of their fort or spaceship game. But the word carries weight: a real commander takes responsibility for their team's well-being and success while earning respect through good decisions and strong leadership. Good commanders combine their authority with care for their team, making decisions that others trust and follow.