Vilfredo Pareto was an Italian economist and sociologist, born in 1848. He is best known for his work in the field of economics and for developing the Pareto Principle, also known as the 80/20 rule, which suggests that roughly 80% of effects come from 20% of causes. This principle has applications in various fields, including business, health care, and time management. In addition to his contributions to economics, Pareto studied social systems and class structures. He introduced the concept of Pareto efficiency, which describes a situation where resources are allocated in the most efficient manner, meaning that no one can be made better off without making someone else worse off. His ideas continue to influence economic theory and social sciences today.