That string is a standard file naming convention used by digital media release groups to identify a specific version of a movie.
: The video compression codec used (also known as AVC). It is highly compatible with almost all modern media players, smart TVs, and computers. Watchmen.2009.Ultimate.Cut.1080p.BluRay.H264.AA...
: The original source material used for the digital encode was a physical Blu-ray disc. That string is a standard file naming convention