Is line of scrimmage the invisible line?

Answer 1

The line of scrimmage is an imaginary line passing through the foremost point of the ball after the ball is marked ready for play. The space occupied by the ball is considered the neutral zone. The defense must stay on their side of the neutral zone and only the snappers hands may be in the neutral zone for the offense. Measurements are taken at the foremost point of the ball and the foremost point must touch the goal line for a touchdown.. When an offense is running out of its own endzone it must get the ball completely out of the endzone or it is a safety.

Answer 2

The line of scrimmage on tv is usually a red line and the first down in a yellow line.