At its core, a compressed game hub takes a 50 GB game and, using algorithms like LZMA, Brotli, or Precomp, reduces it to 15 GB or less. When you download from a compressed game hub, you are not downloading a "cut-down" or "demo" version of the game (usually). You are downloading the full game that has been archived so tightly that it requires an offline decompression process to install.
: Version 5.0.0 introduced full Steam integration, allowing users to log in and sync their library directly. compressed game hub