This code creates an amount of 1 pixel wide divs equal to the width of the users screen, then assigns the background color of each div to be 1 unit of color different(rgb(0,0,0)->rgb(0,0,1)) to the div to the left. After it has gone through every div, it restarts the process but changes the first divs color to be the same as the div on its right, thereby making a color cycle animation the scrolls from right to left.