In this page we post official release notes and changelogs related to Blender 2.91, if and as software developers make available these. However, if you need more info on Blender 2.91, or relases notes are not available yet, you can always consider to read its description as well.
The fourth major release in 2020 is here to further improve the user experience, adding powerful new booleans, better cloth sculpting with support for collisions, volume objects modifiers, improved animation tools and so much more.