In everyday use, a vegetable is any part of a plant that is consumed by humans as food as part of a meal. The term vegetable is somewhat arbitrary, and is defined largely through culinary and cultural tradition. It normally excludes other plant-derived foods such as fruits, nuts, and cereal grains, but includes seeds such as legumes. The original meaning of the word plant, still used in biology, was to describe all types of plants, as in the terms "plant kingdom" and "plant matter."
Vegetables were originally gathered from the wild by hunter-gatherers and entered cultivation in various parts of the world, probably during the period 10,000 BC to 7,000 BC, when a new agricultural way of life developed. At first, plants that grew locally would have been cultivated, but as time passed, the trade brought in exotic crops from elsewhere to add to the domestic types.
Today, most vegetables are grown around the world as climate permits, and crops can be grown in sheltered environments in less suitable locations. China is the largest producer of vegetables and the global trade in agricultural products allows consumers to buy vegetables grown in distant countries. The scale of production varies from subsistence farmers who provide their family's needs for food, to agribusinesses with large areas of single-product crops. Depending on the type of vegetables in question, the harvesting of the crop is followed by sorting, storage, processing and marketing.
Vegetables can be eaten raw or cooked and play an important role in human nutrition, being mostly low in fat and carbohydrates, but high in vitamins, minerals and dietary fiber. Many nutritionists encourage people to eat plenty of fruits and vegetables, five or more servings a day is often recommended.
A vegetable can be defined as "any plant, part of which is used for food", a secondary meaning being "the edible part of said plant". A more precise definition is "any part of the plant consumed for food that is not a fruit or a seed, but including ripe fruits that are eaten as part of a main meal." Outside these definitions are edible mushrooms (such as mushrooms) and edible algae, which, although not parts of plants, are often treated as vegetables.
