1. Size: Violas are generally larger than violins, with an average body length of around 16.5 inches compared to 14 inches for violins.
2. Shape: The body of a viola is slightly wider and deeper than that of a violin, and the shoulders are more rounded.
3. Scroll: The scroll of a viola is typically larger and more ornate than that of a violin.
4. Fingerboard: The fingerboard of a viola is longer and wider than that of a violin, and the spacing between the frets is greater.
5. Strings: Violas have four strings, tuned C, G, D, and A, whereas violins have four strings tuned G, D, A, and E.
6. Sound: Violas have a lower, richer sound than violins, due to their larger size and lower string tension.