@thomasfuchs every Debian Stable numbered release is equivalent to an Ubuntu LTS. They only release about every other year, similar to Ubuntu LTS cadence.
Debian has rolling builds in between called testing and unstable if you want newer packages than latest numbered stable but they don't cut releases every 6 months like Ubuntu.
@thomasfuchs Others have talked about Debian LTS and the debian stable/testing distinction. But you will also want to know about Debian Backports.
Debian Backports lets you get targeted packages from debian testing on your debian stable machine, in a minimally disruptive way. This includes kernels so it is akin to Ubuntu's HWE.
"debian-backports-sloppy" lets you get targeted packages from debian testing on your debian "oldstable" machine, at the risk of making upgrades from oldstable to stable not work due to conflicting package versions.
Debian Backports provides new packages with new features on supported Debian stable releases:
trixie-backports provides new packages for Debian 13 (trixie), backported from Debian testing (forky), which will be updated until 1 year after the forky release
bookworm-backports provides new packages for Debian 12 (bookworm), backported from Debian 13 (trixie), which will be updated until August 9th 2026.
bookworm-backports-sloppy provides new packages for Debian 12 (bookworm), backported from Debian testing (forky), which will be updated until August 9th 2026.
All older branches have reached end-of-life and are no longer supported or updated