Biological classification is the process by which scientists group living organisms. Organisms are classified based on how similar they are. Historically, similarity was determined by examining the physical characteristics of an organism but modern classification uses a variety of techniques including genetic analysis.
Organisms are classified according to a system of seven ranks:
1. Kingdom
2. Phylum
3. Class
4. Order
5. Family
6. Genus
7. Species
For example, the honey bee (Apis mellifera) would be classified in the following way:
1. Kingdom = Animalia
2. Phylum = Arthropoda
3. Class = Insecta
4. Order = Hymenoptera
5. Family = Apidae
6. Genus = Apis
7. Species = Apis mellifera
Species names are always written including the Genus in either full or abbreviated, for example, Apis mellifera or A. mellifera respectively.