A vortex ring is a three-dimensional structure formed when a fluid, such as air or water, moves in a circular motion. This phenomenon occurs when a fluid is expelled from a source, creating a toroidal shape that can travel through the surrounding medium. Vortex rings are commonly observed in smoke rings and bubbles, where the fluid's motion creates a stable, rotating mass. These rings can be studied in various fields, including fluid dynamics and aerodynamics. They are important in understanding how fluids behave and interact with their environment, influencing applications in engineering and environmental science.