A soliton is a self-reinforcing wave that maintains its shape while traveling at a constant speed. It occurs in various physical systems, such as water waves and optical fibers, where non-linear effects balance dispersion. This unique property allows solitons to propagate over long distances without losing energy or form. Solitons were first discovered in the context of fluid dynamics by John Scott Russell in 1834. They have since been studied in mathematics and physics, leading to applications in fields like fiber optics, plasma physics, and quantum field theory. Their stability and persistence make them a fascinating subject of research.