Computational models are those mathematical models in the disciplines of computer science and engineering that require extensive computational resources to study the behavior of a complex system by computer simulation. The system under study is often a complex nonlinear system for which simple, intuitive analytical solutions are not readily available. On the other hand, the development of computational models and computational intelligence systems was inspired by observable and imitable aspects of intelligent activity of the human being. The essence of the systems based on computational intelligence is to process and interpret data of various natures so that computational intelligence is strictly connected with the increase of the available data as well as capabilities of their processing. The theories of computational intelligence developed so, were applied in many fields of engineering, data analysis, forecasting and many others. These mathematical, computational and computational intelligence models are used in images and sounds processing and identifying, signals processing, multidimensional data visualization, diagnostic systems and expert systems etc.