Vegetable is a nutritional and culinary term denoting any part of a plant that is commonly consumed by humans as food, but is not regarded as a culinary fruit, nut, herb, spice, or grain. In common usage, vegetables include the leaves (e.g. lettuce), stems (asparagus), and roots (carrot) of various plants. But the term can also encompass non-sweet fruits such as seed-pods (beans), cucumbers, squashes, pumpkins, tomatoes, avocadoes, green peppers, etc.; even some seeds (peas and beans) that are easily softened by soaking.
Commercial production of vegetables is a branch of horticulture called olericulture.