I am guessing that you mean the names that we give to organisms when they are first discovered and described - the Genus, species name? This is referred to as the "binomial name" and is the end point of the Biological Classification system. We always italicize the Genus, species (and capitalize Genus while leaving the species lower case). Sometimes you see a third name - the "epithet" of the species name.There is quite a bit of history behind the answer to this naming question, but the short answer is that the naming is based on a taxonomic system or code developed by Carl Linneaus in the 1700s. This was pretty controversial back then. The idea is to name living things in a way that helps us "organize" them into related groups (a taxonomy) based on their forms and traits. Many names are based on Latin words (sometimes Greek) and often, the discoverer's name is embedded in the species name (especially in epithets). Recently, some newly discovered organisms have been named as a result of e-bay auctions -- the highest bidder gets to name the organism! But the names still tend to follow the "rules" of the Linnean taxonomy.