Most of the properties of this fractal are common with the Classic Mandelbrot Set, and the applet works identically, so there is not much to explain about it. The only difference is in its calculation formula:

z_{n + 1} =
z_{n}^{4} + c

As you can see, the only difference is in the power of z. Also you will notice that all the Julia Sets of this type will have rotational symetry of order 4, instead of 2.