Hi!
So there is a need for scientific names, and I'll tell you why.
Scientists and researchers need to have a "universal language", so they can communicate with others around the world. They use scientific names that normally have Latin origins.
The reason we use common names is so people don't get confused. Normal people won't go around saying they need to walk their canis lupus familiaris. They'd say they need to walk their dog.
Hope this helps ya out fam!
~theLocoCoco