Short for Fractal Image Format, a graphics file format from Iterated Systems, Inc. that uses fractal geometry to compress images. (Fractals are structures possessing similar-looking forms of many different sizes. They can be used to create any real-world object, like a mountain or a cloud, provided it doesn't correspond to a simple geometric shape.) These fractals can be expressed in mathematical terms, allowing an entire image to be recorded as repeated patterns. This can reduce the file size to 1/100th of a pixellated version.