: If "Arrow S1" refers to Season 1 of the TV series "Arrow," which is a superhero show based on the DC Comics character Green Arrow, then you're likely looking for information on a specific episode or aspect of the show. The extra quality could pertain to video quality (e.g., HD, 4K) or a subjective assessment of the episode's quality.
When you click a result, you should see a list of files that looks like this: index of arrow s1 extra quality