Originally a French term used to describe an area's characteristics, the word is derived from "terre", which means "land", and it's just a small part of the concept. The idea is that a piece of land or field is defined by soils, microclimates, topography and cultivation method. These circumstances are unique and characteristic of the planted vines, of which one can almost say that the wine soil and area are sampled in the finished product.
That Italy in 2011 was the worlds largest wine producer?