Why do we need scientific name where we actually don't use it often?

Common names vary from place to place and language to language, but scientific names in Latin remain the same and are recognizable anywhere in the world. So though we may use common names in our country or state to identify a particular plant or animal, there would be confusion if we use that name in another state or country where the same organism is referred to by another name. Scientific names are important because they are exact: one name for one kind of organism.