>>364382851
Unity uses light probes to determine how bright the ambient lighting in an area is.
The anchor point for a mesh defines where it samples the light probes from (it's always from 1 point, usually the center). People set an "Anchor Override" so that two meshes are guaranteed to share the same lighting info. This eliminates weird seams or discrepancies between different meshes, such as your shoes being noticeably lighter because they're closer to the floor.