In trying to categorize documentaries, it's clear they can fit into both movie and TV show classifications. A documentary can be a standalone film, screened in cinemas or distributed online, which would group it with movies. However, many are serialized and aired on television or streaming platforms, making them similar to TV shows. Ultimately, the distinction depends on the length, format, and distribution method of the documentary. Hence, it's safe to say, documentaries can be either movies or TV shows.