As an example of the latter, the son of John means exactly the same thing as John's son, only using more words instead of the possessive. The linguistic term for this is periphrasis. Outside of such technical considerations, the more common usage is the generic -- and it is generally considered bad style. Bloviation often relies on periphrastic recrudescence. As for its origin, like most terms from rhetoric, it was adopted directly from Ancient Greek (being well-spoken was important to the ancient Greeks, and they spent a lot of time and effort studying how to speak well -- and how to train budding politicians to do it) from an adjectival form of periphrázein, to use periphrasis, which in turn comes down to peri-, around + phrazein, to speak. To speak around the topic, instead of just saying it already. Finally, I leave you with the following self-demonstrating usage of the word, taken from Waverly by Sir Walter Scott:
But without further tyranny over my readers, or display of the extent of my own reading, I shall content myself with borrowing a single incident from the memorable hunting at Lude, commemorated in the ingenious Mr. Gunn's essay on the Caledonian Harp, and so proceed in my story with all the brevity that my natural style of composition, partaking of what scholars call the periphrastic and ambagitory, and the vulgar the circumbendibus, will permit me.Circumbendibus indeed, Sir Walter.