This is the default toolbar. It has a
On the left and right of the toolbar the previous and next tracks are shown and can be chosen by simply clicking on them.
A progressbar with the already played time on the left and remaining time on the right shows the current position in the song.
By using the slightly transparent buttons next to the text you can add the current song to your loved tracks on last.fm or add a position marker.
There is also an option to change the volume.
The slim toolbar has the same functionality as the main toolbar, but it is more compact. It has all buttons concerning the current track on the left and only the volume control on the right side.