Particle interactions refer to the way in which particles, such as subatomic particles or elementary particles, interact with each other through fundamental forces like electromagnetism, weak nuclear force, and strong nuclear force. These interactions determine the behavior and properties of particles, as well as the dynamics of particles within a system. Studying particle interactions is crucial in understanding the fundamental nature of matter and the universe, and it plays a key role in areas such as particle physics, cosmology, and quantum field theory. Scientists use sophisticated detectors and accelerators to study and analyze particle interactions in experiments in order to gain insight into the fundamental forces and particles that govern the universe.