The player reads the songs from a standard ISO disc and uses the folders and sub-folders as directory names. Depending on how you want to sort them you can have them by album, by artist, by genre, etc.
I have mine by artist, then album.
To go to the next folder/album you simply push the up/down button on the fascia and (after a few seconds) it displays the next folder name. It then comes up with the ID3 tag information (only v1.1 at the moment) with song title and artist scrolling across the display.
I assume that you would have to know more or less what was on the CD to find it, just like looking through a CD collection at home.
I have all my MP3 CDs labeled and try to keep to one artist per CD - unless I only have one album of course.
This is the US equivalent of mine - KDC-MP8017 (KDC-MP6090 in UK)
The more expensive alternative
And their latest idea . . .