Vegetable generally refers to an edible part of a plant. The definition is traditional rather than scientific. It is somewhat arbitrary and subjective, as it is determined by individual cultural customs of cooking and food preparation.In general, with some exceptions, any herbaceous plant or plant part which is regularly eaten as food by humans, would normally be considered to be a vegetable. Vegetables are very often eaten cooked. Some, such as potato, are never eaten raw, but many such as carrots, bell peppers and celery are quite commonly eaten either raw or cooked.Mushrooms, though belonging to the biological kingdom Fungi, are also loosely considered as vegetables.In general, vegetables are regarded by cooks as being most suitable for savory or salted dishes, rather than sweet dishes, although there are many exceptions, such as pumpkin pie, etc.Nuts, seeds, grains, herbs, spices and culinary fruits (see below), are not normally considered to be vegetables, even though they are all parts of plants.Some people would consider that salad greens such as lettuce are not vegetables, because they are almost never cooked, but not everyone would agree with this exception.