Hilchos Maasei Hakarbanos 1:17

All of the preceding offerings are called zevachim (from the word meaning to slaughter an animal). Burnt offerings, sin offerings, guilt offerings and the two Shavuos peace-offering sheep are called “kodshei kodoshim” (sacrifices of greater sanctity). The peace offerings of private individuals, firstborn animals, animal tithes and the korban Pesach are called “kodshim kalim” (sacrifices of lesser sanctity).

Hilchos Maasei Hakarbanos 1:18

The limbs burned on the altar from sin offerings that are eaten, guilt offerings and peace offerings are called “eimurin.” The eimurin of an ox or a goat include the fat on the internal organs, including the fat on the abomasum (one of the stomachs), the two kidneys with the fat on them, plus the fat on the abdomen, and the lobe of the liver; a little bit of the liver must be taken with the lobe. In the case of sheep offerings, one must also include the entire fat tail with its vertebrae from the spine until adjacent to the kidneys. This is as per Leviticus 3:9: “He shall remove it opposite the kidneys.” All the eimurin were burned on the outside altar (i.e., the copper altar, on which offerings were burned).