Most seeds come from fruits that naturally Free themselves from the shell, unlike nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. The general and original usage of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pecans, pistachios, walnuts, and Brazil nuts,[1] are not nuts in a botanical sense. Common usage of the term often refers to any hard-walled, edible kernel as a nut.
A variety of species can provide edible seeds. Of the six major plant parts, seeds are the dominant source of human calories and protein. The other five major plant parts are roots, stems, leaves, flowers, and fruits. Most edible seeds are angiosperms, but a few are gymnosperms. The most important global seed food source, by weight, is cereals, followed by legumes, and nuts