Who cares? Neither one is a ukulele!
Okay, because I’m a librarian…
There is no difference between a fiddle and a violin.
According to johnsonstring.com, “A violin and a fiddle are the same four-stringed instrument, generally played with a bow, strummed, or plucked. They are identical in their physical appearance. What distinguishes a violin from a fiddle is the style of music that is played on the instrument; it’s all in how you play it.
The term violin is most often associated with classical music, orchestras, symphonies, and chamber music. Fiddle, in contrast, is associated with a wide variety of music styles including Cajun, bluegrass, folk, and country.”