Yes there is a difference. The wood on the fiddle is going to be a little thinner than the wood in a violin. The Violin is going to be thicker because the strain from the strings.
The viola is larger than the violin, with the viola typically being around 2-3 inches longer in body length compared to the violin. This difference in size also affects the sound and range of the instruments.
I have seen, on this site, several answers which make the violin and the fiddle identical instruments. In fact, my teacher, Boris Schwarz, used to call his instrument a fiddle (though he played classical violin). There is a difference, however, between the two. On the violin, the bridge has a typical curve that raises the strings and separates them from one another. Bariolage (moving from string to string and back again rapidly) is possisble because of the nature of this bridge. However, on a fiddle the artist might NOT want this traditional curve to the bridge and ask the maker to REDUCE the curve of the bridge to make bowing and double stopes easier.
The size of a Violin is measured by the size of the body only. A 4/4 ("Full Size") Violin tends to have a body size of around 14 inches. As violin sizes are non-standardized, this size will vary depending on who made the violin, when it was made and where.
It depends on your electric violin. A hollow-body violin with an acoustic pickup (basically, a traditional violin with a microphone built into it) will make sound just like a standard acoustic violin. A solid-body electric violin will make sound without an amp...but unless you're the violin player, you won't hear it.
Spruce or maple.
The viola is larger than the violin, with a longer body and longer strings.
A violin-shaped bass guitar has a unique design that resembles a violin, offering a distinctive look and feel. It typically has a smaller body size and a curved shape, making it more comfortable to play for some musicians. The benefits of a violin-shaped bass guitar include its lightweight and compact design, which can make it easier to transport and play for extended periods. Additionally, the violin shape can provide a different tone and resonance compared to traditional bass guitars, offering a unique sound for musicians looking for a distinct and unconventional instrument.
The head, the neck, and the body.
On your chin in the chin rest.
The fiddle or viol had a much more guitar-shaped body and a different shape of soundhole. They also lacked a soundpost, which dramatically altered the sound.
wood . ( unless electric then it is metal)
Mostly wood.