A fruit consists of a fertilized ovary with one or more seeds.

The wall of the fertilized ovary thickens into layers of pericarp surrounding seeds.

Fleshy fruits (tomato, grapefruit, nectarine) attract animals which eat the fruit and aid in dispersal of the indigestible seeds.

Dry fruits (milkweed, hazelnut) are often adapted for dispersal by wind or water, or by animal carriers.