Fluid mechanics (fluidics) is the study of motion of fluids (liquids and gases) and the forces associated with that motion. In Chapter 6 we introduce fluidics, compare various fluidic propulsion mechanisms, and discuss the influence of miniaturization on fluid behavior. Our treatment deals with macroscale, microscale, and nanoscale fluidic phenomena. Given the current academic and industrial interest, fluidics in miniaturized analytical equipment is detailed in this chapter as well. Example applications we discuss include electro-osmotic pumping systems, diffusive separation systems, micromixers, DNA amplifiers (PCR), compact disc diagnostic platforms, and cytometers.