This Lattice-Boltzmann method is a popular method for modeling fluid flow. This book, which is a revised revision of a master degree thesis, first covers the foundations of the Lattice-Boltzmann method in the Boltzmann equation, considering its derivation, physical interpretation, and the collision operator, as well as how the Navier-Stokes equations for fluid flow are derived. Simulations with the Lattice-Boltzmann method demonstrate how flow patterns fit with analytical theory for simple flow patterns such as Poiseuille and Couette flow. More complex flows where there is an irregularity to the channel are then investigated, with a focus on the effect such irregularities have on the pressure and velocity field. The appendix includes a working code for Lattice-Boltzmann method written in MatLab.