DOC: Vino a denominazione di origine controllata
(DOC), translated as controlled denomination of origin.
Wines grown in DOC regions must meet strict standards pertaining to production areas, grape varietals grown, grape yield per acre, alcohol content, and other specific growing, aging, and fermenting requirements.
There are over 300 DOCs in Italy.
DOCG: Vino a denominazione di origine controllata e garantita (DOCG), translated as controlled and guaranteed denomination of origin.
Wines grown in DOCG regions have the same strict set of guidelines as DOCs. They are also subject to a taste test and a chemical analysis.
In Italy, there are just over 30 DOCGs, mostly in Piemonte (Piedmont) and Tuscano (Tuscany).
IGT:Indicazione Geografica Tipica (IGT), table wines with a style typical to the place where they are made. Introduced in 1992 it was created to recognize the unusually high quality of the class of wines known as Super Tuscans.
IGT wines are labeled with the locality of their creation, but do not meet the requirements of the stricter DOC or DOCG. Without these restrictions wine makers are free to make better more creative wines. There are over 125 such Regions.