See http://www.debian.org/ for information about Debian GNU/Linux.
Four Debian releases are available on the main site:

Debian 10.13, or buster.  Access this release through dists/oldoldstable
Debian 10.13 was released Saturday, 10th September 2022.

Debian 11.7, or bullseye.  Access this release through dists/oldstable
Debian 11.7 was released Saturday, 29th April 2023.

Debian 12.1, or bookworm.  Access this release through dists/stable
Debian 12.1 was released Saturday, 22nd July 2023.

Testing, or trixie.  Access this release through dists/testing.  The
current tested development snapshot is named bookworm.  Packages which
have been tested in unstable and passed automated tests propagate to
this release.

Unstable, or sid.  Access this release through dists/unstable.  The
current development snapshot is named sid.  Untested candidate
packages for future releases.

Older releases of Debian are at http://archive.debian.org/debian-archive

--- Other directories:
doc             Debian documentation.
indices         Various indices of the site.
project         Experimental packages and other miscellaneous files.
tools           Tools for creating boot disks and booting Linux.