After an animal has been properly slaughtered, there are three parts which must be removed before the meat is kosher: the suet, the sciatic nerve, and the blood. We will now address all three.
In domesticated animals, the Torah prohibits eating ĥelev. Loosely translated as suet, ĥelev refers to certain prohibited fatty parts (as opposed to shuman, which is kosher fat). When a sacrifice was offered in the Temple, the ĥelev was offered on the altar while the rest of the meat was eaten by the priests and the person who brought the offering. Since this fat was designated for sacrifice, it was forbidden to eat. Properly identifying and removing the ĥelev requires expertise acquired through apprenticeship and training.
