Release 25.0.0 is the first release in the Horizon 25 series.
It contains a huge number of bug fixes and enhancements, most notably massive thresholding improvements, big changes to netflow and other streaming telemetry data, reporting and UI updates, plus much more.
The codename for 25.0.0 is Baozi.
For an overview of what has changed since Horizon 24, see What's New in OpenNMS Horizon 25. For a complete list of changes, see the Horizon 25.0.0 release notes.