explaination

A fruit is a ripened ovary. After the ovule in an ovary is fertilized in a process known as pollination, the ovary begins to ripen. The ovule develops into a seed and the ovary wall pericarp may become fleshy (as in berries or drupes), or form a hard outer covering (as in nuts). In some cases, the sepals, petals and/or stamens and style of the flower fall off. Fruit development continues until the seeds have matured. With some multiseeded fruits the extent to which the flesh develops is proportional to the number of fertilized ovules.[12]
The wall of the fruit, developed from the ovary wall of the flower, is called the pericarp. The pericarp is often differentiated into two or three distinct layers called the exocarp (outer layer - also called epicarp), mesocarp (middle layer), and endocarp (inner layer). In some fruits, especially simple fruits derived from an inferior ovary, other parts of the flower (such as the floral tube, including the petals, sepals, and stamens), fuse with the ovary and ripen with it. The plant hormone ethylene causes ripening. When such other floral parts are a significant part of the fruit, it is called an accessory fruit. Since other parts of the flower may contribute to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms.[4]
Fruits are so varied in form and development, that it is difficult to devise a classification scheme that includes all known fruits. Many common terms for seeds and fruit are incorrectly applied, a fact that complicates understanding of the terminology. Seeds are ripened ovules; fruits are the ripened ovaries or carpels that contain the seeds. To these two basic definitions can be added the clarification that in botanical terminology, a nut is a type of fruit and not another term for seed.[2]
There are three basic types of fruits:
Simple fruit
Aggregate fruit
Multiple fruit

Simple fruit
Simple fruits can be either dry or fleshy and result from the ripening of a simple or compound ovary with only one pistil. Dry fruits may be either dehiscent (opening to discharge seeds), or indehiscent (not opening to discharge seeds).[13] Types of dry, simple fruits (with examples) are:
achene - (buttercup)
capsule - (Brazil nut)
caryopsis - (wheat)
fibrous drupe - (coconut, walnut)
follicle - (milkweed)
legume - (pea, bean, peanut)
loment
nut - (hazelnut, beech, oak acorn)
samara - (elm, ash, maple key)
schizocarp - (carrot)
silique - (radish)
silicle - (shepherd's purse)
utricle - (beet)
Fruits in which part or all of the pericarp (fruit wall) is fleshy at maturity are simple fleshy fruits. Types of fleshy, simple fruits (with examples) are:
berry - (tomato, avocado)
stone fruit or drupe (plum, cherry, peach, olive)
false berry - accessory fruits (banana, cranberry)
pome - accessory fruits (apple, pear, rosehip)

fruits

The term fruit has different meanings depending on context. In botany, a fruit is the ripened ovary—together with seeds—of a flowering plant. In many species, the fruit incorporates the ripened ovary and surrounding tissues. Fruits are the means by which flowering plants disseminate seeds.[1] In cuisine, when discussing fruit as food, the term usually refers to those plant fruits that are sweet and fleshy, examples of which include plums, apples and oranges. However, a great many common vegetables, as well as nuts and grains, are the fruit of the plant species they come from.[2] No single terminology really fits the enormous variety that is found among plant fruits.[3] The cuisine terminology for fruits is inexact and will remain so. The term false fruit (pseudocarp, accessory fruit) is sometimes applied to a fruit like the fig (a multiple-accessory fruit; see below) or to a plant structure that resembles a fruit but is not derived from a flower or flowers. Some gymnosperms, such as yew, have fleshy arils that resemble fruits and some junipers have berry-like, fleshy cones. The term "fruit" has also been inaccurately applied to the seed-containing female cones of many conifers.[4]
With most fruits pollination is a vital part of fruit culture, and the lack of knowledge of pollinators and pollenizers can contribute to poor crops or poor quality crops. In a few species, the fruit may develop in the absence of pollination/fertilization, a process known as parthenocarpy.[5] Such fruits are seedless. A plant that does not produce fruit is known as acarpous, meaning "without fruit".[6]