Browsing / Loading

It seems that there are browsing operations that can be performed on both USB storage devices and on discs, others that can only be performed on one or the other. Just what can be done with USB storage devices and what can be done with discs?

For USB storage devices, in addition to folder browsing, if a library is created ahead of time with rekordbox, library browsing is also possible on the CDJ. With library browsing it is possible to select or search for tracks by displaying the category specified for the tracks in rekordbox (ALBUM, ARTIST, TRACK, PLAYLIST, HISTORY, etc.). With discs, only folder browsing is possible.