The string is a specific file naming convention typically used on file-sharing and torrent websites.
: Episode 26 of this season typically covers the Power of Veto competition or the lead-up to a live eviction during the "Final 8" or "Final 7" stage of the game. world4ufree-cfd-bb-s16-e26-hevc720p-mkv
: Standing for High Efficiency Video Coding (also known as H.265), a compression standard that provides high video quality at smaller file sizes. The string is a specific file naming convention