What "fly ball" means in baseball

In baseball, a fly ball refers to a batted ball that is hit high into the air, typically above the height of the outfield fence. When a fly ball is hit, the fielders in the outfield must judge the ball's trajectory and position themselves to make a catch before the ball hits the ground. If a fielder catches a fly ball before it touches the ground, the batter is out and the play is over. However, if the ball is not caught and lands on the ground, the batter may advance to one or more bases.