Zoology is one of the branches of biology, one that is interested in animals in a complete and comprehensive sense of the term. The word zoology comes from the Greek in which zoo means "animal" and logos "science" or "knowledge". Zoology works with different elements related to animals, from anatomical issues such as how the organism is composed, through issues of behavior, habits and reactions to different situations. Zoology classifies animals into different groups taking into account issues such as anatomy, the habitat in which they exist, food, social and individual behaviors, etc.
We can say that while the idea of zoology existed before Darwin, it was this English scientist and researcher who led it to stupendous growth by collecting and publishing information and data on countless numbers of animal species, their morphic characteristics, their behaviors, habitats and the rest. Since then, zoology has established different criteria and classifications that allow us to know in more detail the different groups of animals that we know on the planet and that until now remained unclassified. In addition, zoology also studies with great interest the emergence of animals on the planet, that is, their biological history, which is, ultimately, also the history of the human being.
Within zoology there are different branches that deal with specific questions relating to various groups of animals. Among them we can mention zoography, one that describes the animals around their specific habitat; anatomy, or that which studies the organisms of animals; animal physiology, interested in the physical and chemical functioning of the different functions of animal organisms; ethology, interested in how animals behave in specific environments including both group and individual issues, habits and lifestyles, etc. Then we can also find branches of zoology destined to work with specific types and species of animals.