An initial segment that is broadcast before a new TV/radio show begins airing its regular installments. Often this production will introduce the show's subject-matter, themes, characters, etc. so that the audiences will be better able to comprehend and enjoy said show once it starts being presented.
I appreciated how this complete-series-on-DVD's bonus-material included the show's prepisode, since it allowed my friends who had never seen the show to know what it was going to involve and what to expect, without my having to explain it all to them myself beforehand.
by QuacksO October 26, 2019