It refers to a cluster of West Germanic languages localized in and around the North Sea. That said, these common dialects from both Germany and The Netherlands hold roots in the Middle Ages ...

when the Germanic tribes settled in certain areas and each developed its own form of West Germanic language. With the nationwide establishing of standard German in the mass media and schools, dialects ...

such as Germanic languages, are often easier to learn. English itself is a West Germanic language, so its grammatical structures and vocabulary share common roots with other languages in this family.