This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book provides necessary information on turbulence, including length and time scales, velocity structure functions, turbulent flow models, and turbulent mixing mechanisms. It also provides the general information on population balance, including methods of population balance equation solution. The book introduces the fractal geometry; and drop breakage and coalescence models developed using multifractal formalism. Low molecular weight surfactants should be superior to high molecular weight polymers in creating emulsions. Formulation of high-quality materials requires knowledge about the interaction between all involved processes. The book discusses multifractals, which appear to be a very successful tool at quantifying intermittency, and the main approach for modeling multiphase flows includes Eulerian–Eulerian modeling. It describes the Lagrangian–Eulerian model and volume of fluid approach.