Emmentaler
Emmental, Emmentaler, Emmenthal, or Emmenthaler is a cheese from Switzerland. It is sometimes known as Swiss cheese in North America, Australia and New Zealand, although Swiss cheese does not always imply Emmental.
The name of this famous cheese comes from the valley of the Emme in the canton of Berne. It has been produced there from the 13th century. Since the construction of the first cheese dairies in the valley from around 1815, the production of Emmental cheese has spread throughout the whole midlands. 
Unlike some other cheese varieties, the denomination "Emmental" was not protected ("Emmentaler Switzerland" is, though). Hence, Emmental of other origin, especially from France and Bavaria, is widely available. Even Finland is an exporter of Emmental cheese.
Emmental is a yellow, medium-hard cheese, with characteristic large holes. It has a piquant, but not really sharp taste. Three types of bacteria are used in the production of Emmental: Streptococcus thermophilus, Lactobacillus, and Propionibacter 
shermani. The holes in the texture readily distinguish Emmentaler AOC from any other cheeses. They appear during the fermentation process and vary in size between that of a cherry and a walnut. When a cheese has reached optimum maturity, the holes may contain water or mineral salts. In the late stage of cheese production, P. shermani consumes the lactic acid excreted by the other bacteria, and releases carbon dioxide gas, which slowly forms the bubbles that make holes.
Emmentaler Switzerland AOC is registered since 2006 as an AOC (Appellation d'origine contrôlée). This “original Emmentaler” has to be aged for a minimum of 4 months. It is produced in a round shape with a natural rind and aged in traditional cellars. The original Emmentaler exists with different age profiles, classic 4 month, reserve 8 month, Premier Cru 14 month. It is produced with raw cow milk adding only natural ingredients (water, salt, natural starters and rennet). Preservatives or ingredients from GMO modified organism are not allowed. Emmental AOC is still produced in small rural dairies.
Emmentaler Switzerland Premier Cru is a special Emmental aged for 14 months in humid caves. It was the first cheese from Switzerland to win the title World Champion at the Wisconsin (USA) Cheese World Championships in 2006. It was nominated best cheese among over 1,700 competitors. For this achievement it has received a place in the Historic Museum in Bern Switzerland.
Gruyere
Gruyère is a hard yellow cheese made from cow's milk, named after the town of Gruyères in Switzerland, and made in the cantons of Fribourg, Vaud, Neuchâtel, Jura, and Berne.
In 2001 Gruyère gained the Appellation d'origine contrôlée status. Since then, the production and the maturation is defined in the Swiss law and all Swiss Gruyère producers must follow these rules. To be accepted throughout Europe as an AOC the “Interprofession du Gruyère” in Switzerland plans to make a transnational AOC with the French producers of Gruyère. Before 2001, some controversy existed whether French cheeses of a similar 
nature could also be labeled Gruyère. (French Gruyère-style cheeses include Comté and Beaufort.) French Gruyère-style cheeses must have holes according to French agricultural law, whereas Swiss Gruyère is a solid cheese with no holes.
Gruyère is sweet but slightly salty, with a flavor that varies widely with age. It is often described as creamy and nutty when young, becoming with age more assertive, earthy, and complex. When 
fully aged (five months to a year) it tends to have small holes and cracks which impart a slightly grainy mouthfeel. To make an 80 kg round of Gruyère cheese, about 800 litres of milk are used.
An international panel of expert judges named a Swiss Gruyere cheese as the 2008 World Championship Cheese. The World Championship Cheese Contest in Madison Wisconsin is the largest international cheese and butter competition in the world.