Who were the Veneti? This is not an easy question to answer.
The Vistula Veneti were called Wends, by German-speaking people. But another theory is that Veneti is a diminutization of venus, as per Latin origins. And for further confusion, Slavs living near Germanic settlements were also called Wends.
The Vistula Veneti hailed from Eastern Poland.
Strabo, the Greek historian, conjectures that the Adriatic Veneti are related to the Veneti of Brittany.
Part of the drama here was that the Veneti were experienced in operating on the ocean, whereas the Romans would have only ever known the waters of the Mediterranean Sea. In particular, ships sailed by the Veneti were faster than the Roman ships.