The authors present in this entry chapter the basic rubrics of models, modeling, and simulation, an un-
derstanding of which is indispensible for the comprehension of subsequent chapters of this text on the
all-important topic of modeling and simulation in Information Communication Systems and Networks
(ICSN). A good example is the case of analyzing simulation results of traffic models as a tool for investigat-
ing network behavioral pattarns as it affects the transmitted content (Atayero, et al., 2013). The various
classifications of models are discussed, for example classification based on the degree of semblance to
the original object (i.e. isomorphism). Various fundamental terminologies without the knowledge of which
the concepts and models and modeling cannot be properly understood are explained. Model stuctures
are highlighted and discussed. The methodological basis of formalizing complex system structures is
presented. The concept of componential approach to modeling is presented and the necessary stages of
mathematical model formation are examined and explained. The chapter concludes with a presentation
of the concept of simulation vis-à-vis information communication systems and networks