The concept of dimorphism is used in the field of biology to refer to the condition of the species of animals or plants with two anatomical aspects or two different forms. It is possible, in this sense, to distinguish between different types of dimorphisms.
Sexual dimorphism is characterized by alterations of physiognomy (body shape) between males and females. This dimorphism is usually present in most species, but with varying degrees.
In the case of reptiles, insects and spiders, for example, females are generally larger than males. The reverse occurs with mammals, a group where males can reach much larger than that of women.
Deer (the male has antlers but not the female) and the lions (the male was noticed by his mane) are two animals with obvious sexual dimorphism. Even in the case of human beings, sexual dimorphism is evident, since the sexual organs of men occur outdoors, while women have more pronounced mammary glands.
Generational dimorphism (alternating between different forms of reproduction in the same species), seasonal dimorphism (changes of colour at the level of the plumage of birds after the breeding season) and ecological dimorphism (changes depending on the relationship with the environment or habits) are other dimorphisms warned by biology.
In geology, dimorphism is the condition of any substance that can crystallize in two different systems.