Baking is the process of transferring high sculpt details onto a normal map texture for a lower resolution version of the model for texture painting.
I’ve made a few new videos for my YouTube channel you can watch if you are interested in this subject.
Baking a Goldfish in 3D Coat 2021
Baking a Rabbit in 3D Coat (older version of 3D Coat)
There are more in depth articles on this website for things relating to texture painting.