What's a 'line of scrimmage'?

What's a 'line of scrimmage'?

Darrin Chiaverini (Football Coach and Professional Athlete) gives expert video advice on: What's a 'football'?; What is the object of a football game?; How many people are on a football team? and more...

It's the point where the offense and defensive line meet. When the quarterback's passing the ball, he can't run past the line of scrimmage before throwing the ball. Also, it's where the big boys play.