Particle Image Velocimetry (PIV) is a flow visualization and measurement technique which uses lasers to illuminate particles in a fluid of interest and record their movement through a digital camera. These images are analyzed through PIV software, and this analysis provides a velocity vector field. This velocity vector field can then be analyzed for parameters of interest. This website explains and demonstrates the fundamentals of PIV imaging and processing for new users to gain an intuitive sense for conducting PIV experiments.