In television, in order to produce the number of episodes in a season and have them deliver on time for airing, networks/studios need to hire more than one director. It isn’t necessary, however, to hire one director for every episode. Therefore, each director is assigned more than one episode to direct within the season. It can be back-to-back episodes, but it isn’t unusual for directors to be assigned episodes that are not in chronological sequence. This is called BLOCK SHOOTING. Each directing is responsible for a “block of episodes” and often times, in order to save time, money and resources, they will shoot scenes from two different episode in one location. This is often applied when location are either expensive or involves long travel distance. For example, in GAME OF THRONES, they have to shoot some scenes in Iceland. It wouldn’t make sense to shoot a scene from one episode, have a company move, and then come back to Iceland again for a later episode. After shooting a scene from one episode, the director we reset the scene, change out actors, wardrobe (if necessary), and shoot a scene from a completely different episode.
The advantage of block shooting is that if you have one location that’s used once in several episodes, you can shoot all scenes on the same day. You pay one location fee, and you move the company to the location only once. Saves time and money. On the other hand, the disadvantage is that actors (and that means the director) have to keep track of where their characters are emotionally in different scenes shot in the same place. That’s difficult, and if someone slips up, you may see reactions that make no sense for the season.