In addition to the tools for working with mesh data described in previous chapters, AMReX provides data structures and iterators for performing data-parallel particle simulations. While these tools can be used to implement pure particle methods, they are particularly suited for methods in which particles interact with data defined on a mesh or a hierarchy of meshes. Example applications include Particle-in-Cell (PIC) simulations, Lagrangian tracers, and particles that exert drag forces onto a fluid. The overall goals of AMReX’s particle tools are to allow users to express a variety of useful operations on particle data, including particle-mesh and particle-particle operations, in a performance-portable and scalable manner. In the following sections, we give an overview of AMReX’s particle classes and how to use them.