arrow tells you that the white player is to move. His name appears in front of his clock 
and the clock is ticking.Ask Kasparov. He knows it much better than me.
I can introduce for you the window and tell you what is for what and how to move.
I assume you are familiar with the chess game. At least at the beginning the arrow tells you that the white player is to move. His name appears in front of his clock and the clock is ticking.
You will probably ignore the clock in most of the time. This is for players who want to limit their time available for thinking. They can do so by changing the zero in
to the number that each of them will have for thinking in minutes. Than after every move they will need to pretend they pushed the clock, by clicking on the 
button. When this happens, the arrow will appear at the other player's area, 
and now his/her clock is ticking.
