That is life

sexual dimorphism

This term refers to scientific morphological differences between males and  female animals.

Of course , also in humans.

Not only in vertebrates, but among the less evolved insects and other animals.

Dimorphism not only occurs in the reproductive organs, but external and internal body characteristics: size of individuals is greater in males than in females, although there are exceptions such as spiders and other species, in which individuals are females larger than males.

In birds, the male has more colorful than the female. In mammals, the male genitalia are outside the body ( penis and scrotum), while females have their reproductive systems internally (ovaries, uterus).

It has been found that the male brain is larger in volume than the female brain. Studies show that this intelligence is equal between men and women .

In plants, varieties are hermaphrodite (male flowers and female flowers on the same individual), and most of them are monoecious ( male flowers on one plant and female flowers on another plant).