In English there is a clear difference between a compound word and a noun phrase. A compound word is a word that has two other words making up its parts which has a slightly, or completely different meaning from its parts. A noun phrase is a collection of words that make up an item, like ‘I found the owner of the dog’ ‘the owner of the dog’ is a noun phrase. In German it is, likely, expressed as a single unbroken string. It doesn’t exactly mean that the Germans have a word for ‘the owner of the dog’ it’s just the way they write noun phrases.