I wish it was that way. I've seen a 20 year old get brass instruments mixed up. Many reference squidward when talking about clarinet, oboe, English horn, and bass clarinet. Unfortunately it isn't just musician vs a 5 year old.
I've had multiple people call my baritone saxophone a trumpet... It's funny and sad everytime
The amount of times people have called my trumpet a saxophone, or my trombone a saxophone, or my clarinet a saxophone, or my melodica a saxophone, or my saxophone a saxophone apauls me.
Never call someone a saxophone; not only is it rude, it's a slur and against the law.
Soundwise or visually? I can see the difference (big vs little) but I don't think I could reliably pick out the sound between the two.
I was thinking visually. But even sound-wise I don't think most people would hear a cello and think that's a violin (even if they don't know it's a cello). But I've listened to a lot of Apocalyptica and 2Cellos, and I also grew up on cartoons that feature tubas frequently for comedic effect, so maybe I'm just biased.
The difference is the bridge. Fiddle has a flatter bridge to make it easier to hit all four strings at once. Violin has a curved bridge to make it difficult to hit multiple strings at once.