Yer Olde Gini Index

Reading in the textbook for my Sociology course I came across the "Gini Index". Here is the definition from Encarta Dictionary online:

"income distribution index: an index of income distribution in an economy, expressed as a fraction, that indicates the level of inequality between incomes. The higher the fraction, the greater the inequality of incomes."

I'm sure the knowledge of this term won't impact your life profoundly; however, I was intrigued by the name. Which, by the way, comes from the Italian statistician Corrado Gini.