A recap episode is a broadcast episode assembled largely from footage of earlier episodes, summarizing the story so far. Recaps exist to give the production a week of breathing room and returning viewers a refresher, and are usually excluded from a series' real episode count.
The recap episode is a production tool disguised as a broadcast. Assembling an episode from existing footage costs a fraction of animating a new one, so a recap buys the staff a week: it airs in the slot, the schedule holds, and the next fully produced episode gets the time it needed. Productions under pressure reach for it, and long series used to reach often.
Recaps also serve the audience honestly in the right dose. A series returning after months away, or a story dense enough that even its fans lose threads, benefits from a well-made summary, and some landmark episodes use the form deliberately, framing old footage inside a new scene to recontextualize it.
The modern environment has shrunk the recap's role. Streaming viewers can rewatch at will, and platforms often label recaps as separate specials (numbered 0 or .5) or skip them in the episode count entirely. When a database and a platform disagree about a series' episode count, a recap is usually the reason. Television stations once valued recaps for a second reason: a viewer who joined a popular series late could be caught up in one sitting, in an era with no rewind.
In use"Episode 14 is clips and narration catching up new viewers: a recap, whatever number the platform gives it."