Pinot Grigio and Pinot Gris are the same grape. However, the two terms tend to denote different styles of wine produced from the grape. The grape is known as Pinot Grigio in Italy, California and Australia and Pinot Gris in Oregon and France. With the American grape, the difference in name denotes a difference of styles.
California Pinot Grigio tends to be a clean, light wine with citrus notes. It is modeled after the Italian Pinot Grigio, which is a light, simple, crisp white wine with noted of lemon, nectarine, and sometimes spice. Australian Pinot Grigio also tends to follow this model.
Alsace, France produces a bold Pinot Gris, with notes of smokiness, bitter almond, spice, honey, and stone fruit. This Pinot Gris tends to be on the drier side and often shows incredible richness and earthy minerality.
Oregon Pinot Gris, however, is a different wine entirely. Oregon Pinot Gris seems to combine the richness of the Alsace style with the vibrant fruitiness of the Californian and Italian styles. Pinot Gris from Oregon tends to be medium bodied with a somewhat creaminess character. It has undertones of pear, mango, honeysuckle, and almond.