This chapter discusses the nature of turbulence, Eulerian and Lagrangian modeling approaches, and formulates the deterministic equation of motion and the solution methods usually used when particulate systems are considered. The chapter presents the microstructure of turbulence and statistical description of turbulence. It analyzes the microstructure of turbulence, including its intermittent character in more detail. The breakage of particles of a size falling within the inertial subrange of turbulence belongs to the second group of processes. The character of turbulence in the range of small scales is, therefore, determined only by parameters resulting from internal conditions: energy dissipation rate, and fluid viscosity, and the state of equilibrium are universal. Kolmogorov assumed also the existence of a finite, non-vanishing mean energy dissipation rate which is one of the most important quantities in three-dimensional turbulence. Two-dimensional turbulence approximation is used by meteorologists to describe cyclones and by oceanographers to describe the dynamics of oceanic currents.