binomial system – the system of naming species using unique two-part scientific names

To remember the meaning of binomial system, use the following mnemonic:

I will buy no meals for you until you use this system (binomial system) to name each species with a two-part name.

The binomial system is the universal naming system for all living organisms, where each species is given a unique two-part scientific name consisting of its genus and species (see taxonomy). The first part of the name indicates the genus (a group of closely related species), while the second part specifies the particular species within that genus. For example, humans are Homo Sapiens, where Homo is the genus and Sapien is the species. While lions are Panthera Leo, where Panthera is the genus and Leo is the species. 

This system is used worldwide by scientists regardless of their native language, ensuring clear communication about organisms without confusion caused by different common names.