Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms.
Cheese consists of proteins and fat from milk, usually the milk of cows, buffalo, goats, or sheep. It is produced by coagulation of the milk protein casein. Typically, the milk is acidified and addition of the enzyme rennet causes coagulation. Rennet is a meat product but vegetarian alternatives to rennet are available. Vegetarains should check the label on cheeses to ensure a cheese is vegetarian. 
The solids are separated and pressed into final form. Some cheeses have molds on the rind or throughout.
Hundreds of types of cheese are produced. Their styles, textures and flavors depend on the origin of the milk (including the animal's diet), whether they have been pasteurized, the butterfat content, the bacteria and mold, the processing, and aging. Herbs, spices, or wood smoke may be used as flavoring agents. The yellow to red color of many cheeses is from adding annatto. Most cheeses melt at cooking temperature.
For a few cheeses, the milk is curdled by adding acids such as vinegar or lemon juice. Most cheeses are acidified to a lesser degree by bacteria, which turn milk sugars into lactic acid, then the addition of rennet completes the curdling.
Cheese is valued for its portability, long life, and high content of fat, protein, calcium, and phosphorus. Cheese is more compact and has a longer shelf life than milk. Cheesemakers near a dairy region may benefit from fresher, lower-priced milk, and lower shipping costs. The long storage life of some cheese, especially if it is encased in a protective rind, allows selling when markets are favorable. For many/most people cheese (other than cottage cheese) is likely a more convenient staple than for example yoghurt as it can be stored safely in the fridge for longer.
Varieties of cheese Edit
Factors relevant to the categorization of cheeses include:
- Length of aging
- Methods of making
- Fat content
- Kind of milk (typically cow, goat, sheep, buffalo or yak)
- Country/Region of Origin
Cheeses that aren't vegetarianEdit
Parmesan is never vegetarian because there is a legal requirements to include calf's rennet. You may be able to get vegetarian, ‘parmesan style hard cheese’ or other vegetarian cheeses that are similar to paremsan. If you can't get vegetarian alternative to parmesan where you live vegetarian cheddar tastes similar. Try adding cheddar while the dish is cooking so the distinctive cheddar taste is less noticeable. Gorgonzola and Grana Padano are also never vegetarian. 
Popular cheeses Edit
This is by no means a complete list:
- Blue cheese
- Cottage cheese
- Cream cheese
- Goat cheese