iTunes HELP

From the help section of iTunes...Understanding the symbols next to songs

When you import songs and work with playlists, symbols next to songs show their status.

? A moving zigzag means a song is being imported from a CD or your hard disk. A green checkmark means iTunes has finished importing the song.
? An exclamation point means the song file can't be located. It may have been moved or deleted.
? A broadcast icon means the song is stored on the Internet and is "streamed" to you when you click to play it.
? A black checkmark means the song will be included in your next action. For example, only songs with black checkmarks are imported when you click the Import button.
? A speaker means the song is currently playing. When importing a song you're also listening to, you see a moving zigzag instead of the speaker.
? Chasing arrows mean the song is being copied or downloaded from the Internet.

When you eject a CD, the symbols related to the songs on it disappear.