Question about an icon on top

[maryinredding]

What does the double circular arrows mean at the top of the screen? It is grayed out but I don't know what I must have pushed to have this come on. Thanks everyone.

 

[maryinredding]

OK, I can answer my own question now. It is a synch button. I never remember seeing it before at least not grayed out. So I went into my synching section and restarted it and now it is gone from the top of the phone. The icons are still checked but I guess it wasn't running before. I think it must have happened when I synched some music to my phone earlier.