The butterfly effect theory proposes that small initial changes in a system can lead to large unpredictable changes later. This was first proposed by Edward Lorenz to describe how minor perturbations like a butterfly flapping its wings could influence a hurricane weeks later. Related concepts like fractal theory and chaos theory also describe how simple deterministic systems can produce complex, unpredictable long-term behaviors due to sensitivity to initial conditions. The butterfly effect and these related theories have real-world applications in domains like weather modeling, climatology, and computing.