(Don't shoot me for having this view...)
Our Creator didn't use a fractalprogram to create clouds, trees, flowers, snowflakes...
You can also draw a fractal with a pencil, you can create a fractal with a lot materials.
or 2D [link]
Benoit Mandelbrot, the inventor of what we know as fractals, meant by fractals:
A fractal is generally "a rough or fragmented geometric shape that can be subdivided into parts, each of which is (at least approximately) a reduced-size copy of the whole," a property called self-similarity. The term was coined by Benoît Mandelbrot in 1975 and was derived from the Latin fractus meaning "broken" or "fractured." (Wikipedia)
Let's restrict fractals to the products of fractalprograms...
Are all products of a fractalprogram fractal ?
Several say: yes. Several say: no.
Is layering a fractalproperty ?
It is in my opinion only the possibility in some fractalprograms to create a nice image with several fractals, but the result is not ONE fractal, but several fractals, blended into one. FractalArt.
Why is this possibility not in all fractalprograms ? Sterlingware is an excellent fractalprogram, but there is no layering function. Stephen Ferguson is very capable of adding this function.
Fractal Explorer has a layering function, but I can insert any image in the fractal with that. Of course: also another fractal, but it still will be a blend of two fractals.
Bringitin is a program to convert any image to a coloralgoritm you can use in Ultra Fractal. In that way you also can insert any image in the fractal. Even in a one layered fractal.
Where do you draw the line ?
You don't need a fractalprogram to create a fractal and not all the products of a fractalprogram are fractals.
There are heated discussions about this. I don't see why. It is not a matter of who is right. We want to have fun with it. Right ?