In the middle ages the "fiddle" at the word's broadest meaning referred to a several different instruments. The bowed type, called in French the "vielle", was the preferred instrument of the troubladours and trouveres. One type had a square body, a rouded pegboard, and five or so strings which (so far as is known) were not tuned in fifths. The violin was invented in the late 1400s, and for a while was just one more species of fiddle. In the end though, it swept almost all other fiddle types before it in the field European-derived art music, though other shapes are still sometimes made. So if a small bowed instrument has four strings, a scrolled pegboard, and f-shaped sound holes, you can call it a violin or a fiddle. If the sound holes or pegbox have some other shape or if the instruments has other than four strings, it's no longer a violin but may still be a fiddle.

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