Also known as the 80/20 rule, the Pareto principle states that 80 percent of the results come from 20 percent of the actions.The principle is named for Vilfredo Pareto, who observed, sometime between 1890 and 1906, that 80 percent of the income in Italy accrued to 20 percent of the population, or that 80 percent of the land was owned by 20 percent of the population, or that 20 percent of the peapods in his garden yielded 80 percent of the peas, or something of the sort, depending on which source you believe.The Pareto principle essentially is the law of the vital few versus the trivial many.