Scattering theory is a framework in physics that studies how particles, such as electrons or photons, interact with each other or with potential barriers. It focuses on understanding how these particles change direction and energy after colliding, which helps scientists predict the outcomes of various physical processes. This theory is essential in fields like quantum mechanics and nuclear physics, as it provides insights into fundamental interactions. By analyzing scattering patterns, researchers can infer properties of particles and forces, contributing to advancements in technology and our understanding of the universe.