Steam-repacks -

"Steam Repacks" are compressed versions of PC games originally distributed on the Steam platform. They are primarily created by third-party individuals or groups to reduce the initial download size, making games more accessible for users with slow internet or limited storage. What is a Steam Repack?

Repackers use tools to shrink game data. For instance, a 100GB game might be compressed into a 30GB to 50GB installer. Steam-Repacks

Collectors use repacks to keep "complete editions" of games (including all DLCs) in a compact format for long-term storage. "Steam Repacks" are compressed versions of PC games

Most repacked games cannot access official Steam servers for multiplayer unless they use specific "online fixes" that simulate a legitimate connection. Steam-Repacks