This is the main screen - the home page if you will - which contains information and controls for basic playback.
If you have enabled album art in the options, the player screen display the album art of the playing song.
It also shows song title, album title, and artist name.
The screen dump above shows two stars next to the song titel. This is the song rating, which can be change by clicking it.
Click these links will take you to the song screen, album screen, or artist screen respectively.
Then you have progress and volume controls.
And finally the title and artist of the upcoming song is shown.