A scoring drive is labeled as such if a team is able to score points. Each time a team gains possession of the ball, a drive has begun. If the team scores, it is referred to as a scoring drive. Without the score, it would just be a drive.
The longer, more plentiful the scoring drives a team has, the better chances that team has to win the game. Field position and time of possession are two key components in an NFL game. A team capable of keeping the opposition in bad field position via kickoffs, and keep the ball out of their hands with long, time consuming scoring drives, will always have the best chance to win. If a drive does not end in a score, that means the team either turned the ball over on downs or punted it away. In the latter case, if the team only played one series it is known as a "three-and-out."