Fractals are typicallyself-similar patterns, where self-similar means they are “the same from near as from far” Fractals may be exactly the same at every scale, or as illustrated in Figure 1, they may be nearly the same at different scales. The definition of fractalgoes beyond self-similarity per se to exclude trivial self-similarity and include the idea of a detailed pattern repeating itself.:166; 18
The DDC attempts to organize all knowledge into ten main classes. The ten main classes are each further subdivided into ten divisions, and each division into ten sections, giving ten main classes, 100 divisions and 1000 sections.