The Advanced Mode is a mode in which you can easily add audio tracks and ISO files (those are CD-images). There is also the possibility of adding your other tracks.
In the filetree you can select .iso files, and audio files. These can be dragged to the track list. There tracktype will be set automagically. It you want to add custom tracks, click on the Add Empty Track button. The Track Dialog will be shown, where you can set the details of the track. You may delete tracks using the Remove Track button. If you want to play the audio tracks, just click on them.
