This book presents the SPH method (Smoothed-Particle Hydrodynamics) for fluid modelling from a theoretical and applied viewpoint. It comprises two parts that refer to each other. The first one, dealing with the fundamentals of Hydraulics, is based on the elementary principles of Lagrangian and Hamiltonian Mechanics. The specific laws governing a system of macroscopic particles are built, before large systems involving dissipative processes are explained. The continua are discussed,