Many products are emulsions, either as industrial intermediate, or as consumer designed products. From the microstructural point of view, emulsions are dispersed systems of at least two insoluble liquid phases. In order to design products according to target consumer needs, property, and process functions have to be known. This review gives an overview of emulsification basics based on the partial stages droplet disruption and coalescence. Emulsification machines and apparatus are described, property and process functions are given. Both, conventional emulsification applications and alternative processes using emulsions for the production of sub-micron solid particles of modified product properties are described.