What Does "Single Vineyard" Mean?

Integral to the concept of high quality wine is the idea of "terrior", or sense of place. In the most famous of Old World wines, this is defined by small vineyards, defined by monks in centuries past. In New World wines, wine-makers are beginning to think about this. According to US wine laws, so long as 95% of the grapes come from a specific vineyard, the wine can be labeled as Single Vineyard or by the name of the vineyard.