Pancetta is cured pork belly meat, it's cured with salt and spices. Bacon is also cured pork product (sometimes pork belly, sometimes loin) but besides being cured, it is also smoked and the process involves nitrites. While they're similar cuts of pork meat (bacon served sliced while pancetta usually diced), pancetta is healthier than bacon because it has lower sodium and doesn't go through the smoking process (so no nitrites). Pancetta is more expensive though.