The "80/20 Rule," also known as the Pareto Principle, suggests that roughly 80% of effects come from 20% of causes. This principle can be observed in various fields, such as business, where a small number of clients often generate the majority of revenue. It highlights the importance of identifying and focusing on the most impactful factors. In personal productivity, the 80/20 Rule encourages individuals to prioritize tasks that yield the greatest results. By concentrating on the vital few activities that drive success, people can work more efficiently and achieve better outcomes with less effort.