Gravity3d20131080pblurayhalfsbsdtsx264 Exclusive Portable

This tells you the source material. The file was "ripped" or encoded directly from a physical Blu-ray disc, which provides much higher bitrates and better image quality than standard streaming versions.

Marks this specific upload as a unique encode, often featuring custom audio syncing, optimized bitrates, or rare audio tracks not found in standard scene releases. Why Gravity is the Ultimate Film for 3D and DTS-X gravity3d20131080pblurayhalfsbsdtsx264 exclusive

Refers to the digital surround sound audio codec used in the file. The compression standard (H.264) used to encode the video. If you are looking for where to watch this legally, This tells you the source material