The name makes sense, so it is difficult to see how it might be wrong. In Ontario, the very restrictive building code makes most railings very plain, with all-vertical elements. With nothing but vertical bars in a row, why wouldn’t it be called a Rod Iron Railing? The whole railing is made of iron rods – what could be more obvious?
But this is trick of the ear, like a misunderstood song lyric. One that you can blame on the building code, on technological progress, and a bad shortage of blacksmiths here in the 21st century.
Iron rods don’t make Wrought Iron
What you mean when you say “Rod Iron”, is in fact “Wrought Iron”. They sound almost identical, and unless you grew up in a blacksmith shop, how are you supposed to know the difference? And while a Rod-Iron seems self-evident, “Wrought Iron” has many different meanings.
Today, it is often used as a catch-all term for any decorative metal railing, whether it is made of wrought-iron, steel, cast iron or even aluminum. Anything but a chain-link fence gets marketed as “Wrought-iron”.
But long ago, wrought iron was both a material, a process, and a style. Blacksmiths work with iron (the black metal), and to be “wrought” means to be worked – to be hammered and shaped and transformed.
Old-time blacksmiths (and modern ones) were particular about their terminology: for a piece to be wrought it must be heated and hammered and bent. This distinguished wrought iron work from bent iron – work that had been bent or formed cold, usually out of thinner flat bars and usually simple and unsophisticated.
Almost all of the “Wrought-iron” ironwork you see today fits this second definition. (Even if the railing is made of iron rods.)
Whether that's good or bad you can decide for yourself.