It looks like you're asking about the "fórum cs.rin" — specifically the cs.rin.ru forum (often written with the accented "ó" in URL-encoded form as f%C3%B3rum).
Here’s a breakdown of deep features of that forum, beyond just being a game piracy hub: f%C3%B3rum cs.rin
Some games are not sold in certain countries. A user in Brazil or Argentina (hence the Portuguese "fórum") might use cs.rin to access a game they legally cannot purchase on Steam due to publisher geo-blocking. It looks like you're asking about the "fórum cs
Even if you exclusively buy your games, cs.rin.ru offers tools you often cannot find anywhere else. Reason 2: Bypassing Regional Restrictions Some games are