Definition
In college football, if a defensive player gains possession of the ball during a play, between his own five-yard line and goal line, and the player's original momentum carries him into the end zone, there is no touchback. Instead, the ball is dead at the point where possession changed. In the National Football League, this rule applies only to pass interceptions (regardless of whether they occur inside the five-yard line).

American Football
In Canadian football, the failure to advance a kicked ball out of the goal area results in a single point being scored by the kickers, as well as possession by the receivers at their 35-yard line. A turn-over by fumble or interception in the defense's goal area results in a scrimmage on the 25-yard line with no points awarded. In the Canadian game the term touchback is not used.