When a film or video is being made it is not shot in a consecutive manner according to the story. That is, there is no progression from Scene 1 on Day 1 to Scene 25 on Day 25 or whenever shooting stops. It is generally shot out of sequence.
Take, for example, the following story:
Two guards are on the battlements of a castle. It is daytime. They see a dusty rider on the road, galloping towards them. One guard reaches for his gun. The rider suddenly reins in his horse and looks up at the castle. We see the rider’s view of the castle.
Cut to a shot of a woman on board ship.
Back to the battlements where one guard is keeping watch on the rider and the other guard runs down some stairs to raise the alarm.
Cut again to the woman on the ship.
Cut to a room in the castle, full of drunken guards. They hear the alarm, leap up and rush from the room.
In order to plan when you are going to shoot each separate piece, this story would be broken down initially into scenes:
Scenes in Story Order:
1. Castle battlements; 2. Dusty rider; 3. Battlements; 4. Rider; 5. Rider’s POV of castle; 6. Woman on ship; 7. Battlements. Guard exits; 8. Guard raises gun; 9. Woman on ship; 10. Mess room of castle.