EMZETT.Debian
In short: Debian is a free, community-developed Linux distribution founded in 1993 by Ian Murdock.
In more detail: It is considered very stable and is the basis of many other distributions (Ubuntu, Linux Mint, Kali). Packages are managed with apt and dpkg.
In Depth
Details
There are the branches Stable (tested, updated slowly), Testing and Unstable (Sid). Debian 12 “Bookworm” was released in June 2023, Debian 13 “Trixie” in August 2025. Popular for servers.