Linnaean hierarchy

Carl Linnaeus developed a hierarchical system for classifying living organisms in the 18th century, organizing them into categories such as kingdom, phylum, and species. Originally based on appearance, modern classification now uses evolutionary criteria. Linnaeus also introduced the binomial naming system, assigning Latin names to species and genus, a method still in use today.

What criteria do we tend to use now for classifying species instead of appearance?

What is the binomial naming system proposed by Linnaeus?