The term fiddle refers to a violin; it is a colloquial term for the instrument used by players in all genres, including classical music. Fiddle playing, or fiddling, is a style of music.

Violin vs. fiddle

Any violin may be informally called a fiddle, regardless of the kind of music being played with it.

Non-violin specific

Fiddle has a more generalized meaning than violin. Whereas violin refers to a specific instrument, fiddle may be used to refer to a violin or any member of a general category of similar stringed instruments played with a horsehair bow, such as the Hardanger fiddle, the Chinese erhu, the Welsh crwth, the Apache Tzii'edo' a 'tl, the cello in the context of a Scottish violin/cello duo ("wee fiddle and big fiddle"), the double bass ("bull fiddle" or "bass fiddle"), and so on.

Etymology

The etymology of fiddle is uncertain: the Germanic fiddle may derive from the same early Romance word as does violin, or it may be natively Germanic.

(as access to the OED online is not free, the relevant excerpt is provided) "The ultimate origin is obscure. The 1 word bears a singular resemblance in sound to its [medieval Latin] synonym vitula, vidula, whence French viole, Pr. viula, and (by adoption from these 2) 3, 4, 5 viola: see [viol[. The supposition that the early 6 vidula was adopted independently in more than one language would account adequately for all the 7 forms; on the other hand, *fiÞulôn- may be an Teutonic word of native etymology, though no satisfactory 8 derivation has been found."

Musical style

Common distinctions between violins and fiddles reflect the differences in the instruments used to play classical and folk music. However, it is not uncommon for classically trained violinists to play fiddle music, and today many fiddle players have some classical training. As might be expected from the differences between the classical and folk music cultures, more musicians with no formal training play fiddle music than play classical music.

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