Species is a special term that is typically used to indicate a group of organisms that are genetically similar enough so that they can successfully breed and produce fertile offspring. We sort organisms into large groups called Domains, and then the Domains are subdivided into Kingdoms, and each Kingdom is then split into Phyla, and so on through Class, Order, Family, Genus, and Species. In some cases Subspecies are also identified.
However, not everything that is a species is alive. Viruses are not considered to be living, as they have no metabolism. However viruses are in fact classified by using a modified definition of species; a viral species is one whose members share an ecological niche and a replicating lineage.
Consequently, while every living organism can be classified as to what species it is, not everything that is a species is a living organism.