Todor Nikolov writes:
The Asset Browser is one of the most notable recent features of Blender. It allows you to organize your Objects, Materials, HDRI maps, and even Geometry Nodes setups.
Built on top of the Asset Browser is the Pose Library which is essential for Riggers and Animators. In it, you can save hand poses, facial expressions, or even full-body poses in the Asset Browser.
The Pose Library only works with static poses (as the name suggests). Full animations are not supported yet but I found a workaround that allows you to create a collection of animations as well.
In the following 3 videos, you can learn about each of these topics
Animation Library Hack