The ability of people or animals to produce healthy offspring in abundance. Unlike fecundity, which measures a potential ability, fertility measures the actual number of offspring of an individual, a couple, a group or a population. It is evaluated by the time to achieve pregnancy. Please note that "fertility" corresponds to "fécondité" in French and "fecundidad" in Spanish whereas the French word "fertilité" and the Spanish word "fertilidad" mean "fecundity".