The Browse by Album section looks at songs metadata and groups first by the album field
If a song does not have a value for Album, then it goes into the UNKNOWN ALBUM section
Filters
This section has the same filters as Browse by Folder plus one other filter:
Cover Art Filter
If set to With Cover Art only shows albums that have a Cover art image in the metadata
MusicBrainz Filter
Example of setting different value for the MusicBrainz filter
No Album Match indicates no songs matched to MB album, (White badge)
With Full Album Match indicates all songs matched to one MB album,(Green badge)
With Split Album Match indicates all songs matched, but to multiple MB album, (Red badge)
With Partial Album Match indicates some songs matched to one MB album, (Orange badge)
When we click on an Album we are taken to the Song Details Summary