Three factors. (1) Purpose: meditation bowls are larger and lower-pitched (7–12 inch); sound-healing practitioners often want specific frequencies matched to chakras; decorative bowls prioritize appearance. (2) Sound: play the bowl before buying — a good bowl sings for 30+ seconds with a single overtone, a poor one dies within 10 seconds or wobbles between frequencies. (3) Construction: hand-hammered bowls show visible hammer marks and irregular rims; cast bowls are perfectly round. Neither is “better” — they serve different buyers.