The concept of a cru (or estate) has always existed, but terroir, a more recent term, is now considered of even greater importance. Terroir explains why some wines are consistently better than others. Although winegrowers obviously leave their mark as well in terms of culture, philosophy, and tradition, some vineyards always produce finer wines.
It could be said that emphasizing the concept of terroir - a combination of soil characteristics and microclimate - has led to the development of winemaking techniques best adapted to the qualities and inadequacies of a given vineyard.
Of course, quality keeps pace with an estate's reputation if the finest terroir receives the best care. Likewise, more modest, or even unknown estates may be coaxed into producing very interesting wines.