What are latin binomials and why do we use them?

The binomal system was invented by Carl Linnaeus in the 1700s. Latin binomials are names we use to identify different species. They come in two parts ('bi' means two, and 'nomial' means name) which identify an organism's genus and species. They tell us which groups each organism falls into and let scientists who speak different languages talk about the same animal in the same language (Latin!).

We group animals at 7 different levels to help us identify them and see how related they are. These groups are:

Kingdom- This is the broadest group, it splits organisms into 5 general groups which are usually easy to tell apart. 
Phylum
Class 
Order
Family
Genus
Species- There are thousands of species! And each organism has its own individual species name. 

An easy way to remember the order of these groups is to use a mnemonic:
King Penguins Climb Over Fat Granny Sue

For example, we can identify the different groups for a red fox below:
Kingdom= Animalia (the group with all the animals in)
Phylum= Chordata (all the animals in the Kingsom Animalia which have a spinal cord)
Phylum= Mammalia (all the Chordata which are mammals)
Order=Carnivora (all the Mammalia which are carnivores)
Family=Canidae (these are dog-like mammals)
Genus=Vulpes (all the canids which are foxes)
Speces= Vulpes (the red fox species name)

This means the latin binomial for a red fox is Vulpes vulpes

You always write the name of the genus with a capital letter at the start and the name of the species with a lower case letter at the start. When you are writing them down you usually underline the whole binomial, or if the name is typed and printed it is usually in italics. ( E.g Homo sapiens or Homo sapiens)