A pine is any conifer in the genus Pinus of the family Pinaceae. Pinus is the sole genus in the subfamily Pinoideae. The Plant List compiled by the Royal Botanic Gardens, Kew, and Missouri Botanical Garden accepts 126 species names of pines as current, together with 35 unresolved species and many more synonyms. Pine may also refer to the lumber derived from pine trees; pine is one of the more extensively used types of wood used as lumber. Some species have large seeds, called pine nuts, harvested and sold for cooking and baking. They are an essential ingredient of pesto alla genovese.
A nut is a fruit composed of a hard shell and a seed, which is generally edible.
There is an additional requirement in botany that the shell does not open to release the seed (indehiscent). In a general context, a wide variety of dried seeds are called nuts, but in a botanical context, only ones that include the indehiscent fruit are considered true nuts.