In cw projects what resides in audio and in audio data folders.

Audio..

Wav files that have been used/recorded in Sonar.

Except if you select the "Use Per-project audio folders" option in the "Preferences / File / Audio data" section, which is better, i guess.

From pg1810 of the Sonar Reference Guide.

Global Audio Folder.The Global Audio Folder is where audio files are stored for all projects when per-project audio is not turned on. It is also used to store audio for older, non-per-project audio projects, as well as a temporary folder for unpacked bundle files and to store audio for as yet unnamed projects