In "distinción" spanish, the classic pair is the word for house and for hunt - "casa" and "caza" respectively. If you pronounce them the same (with an S sound), you're a Seseo speaker like (most) latin america. If you pronounce them with different sounds, one an S sound, the other a TH sound, you're a "distinción" speaker, and if you pronounce them both with a TH sound, it's the more uncommon ceceo accent, usually largely Andalusian.