While following the hierarchy of classification, it is the species which is the group with the smallest number of organisms having maximum characteristics in common or similar.
In biology, the hierarchy of classification has 8 major ranks. The taxonomic ranks start with species followed by genus, family, order, class, phylum, kingdom, domain leading to life. Here, the class is defined as that taxonomic order where organisms are classified with their common general traits or characters that all of them possess in common like having a backbone called as vertebrates or not having the backbone are called as invertebrates. An order is a taxonomic rank which is used in the classification of organisms. The family is that taxonomic group where organisms of same genera are put together like tigers and cat belong to the same family Felidae.