F1 Goldendoodles are a cross between a Golden Retriever or (Labrador Retriever) and a Poodle.
F1B Goldendoodles are a cross between a Goldendoodle and a Poodle.
F2 Goldendoodles are a cross between an F1 Goldendoodle and an F1 Goldendoodle.
Multi Generational Goldendoodles are a cross between an F1B Goldendoodle and an F1B or Multi Generational Goldendoodle
(there are other ways to achieve multi gen cross)
North American Retrievers, or Double Doodles are a cross between a Goldendoodle and Labradoodle