Abstract: The Brockhaus and Efron Encyclopedic Dictionary recognizes classification (from Lat. classis- class, category and Lat. facere - to do) as "special cases of application of the logical operation of division of the amount of term via a certain combination of divisions (division of a class into types, division of these types, etc.)". "Classification is a meaningful order of things, events, dividing them into types in according to some important characteristics". Any classification in science or any other sphere of activities is meant for the constant practical use, that is why it should at the same time enclude the entire complex of necessary parameters, and it should be simple and easy to comprehend.  Usually, the classifications use significant features of objects as dividing elements for their classification. Such classifications are known as natureal, since they reveal significant similarities and differences between objects and have cognitive value. If the classifications are aimed at systematizing the objects, the dividing elements are chosen out of convenient ones given the purpose of classification, but not necessarily significant for the objects themselves. Such classifications are called artificial.