Traditional Jewish practice forbids the consumption of some types of food (certain varieties of animals, animals slaughtered by any but the accepted method, the blood of mammals or birds) and some combinations of foods (roughly, meat with milk products). It mandates kitchen practices that help maintain those restrictions. These laws, known collectively as kashrut (literally, "fitness"), are observed in varying degrees among Jewish families and individuals. For those who choose to observe some or all of the system of kashrut, it serves as a frequent reminder of their distinct identity as Jews.
Many explanations have been offered for each aspect of kashrut. The Torah suggests that the Israelites attain unique holiness through food restrictions that distinguish them from other peoples. Some later explanations are framed in behavioral categories internal to Judaism, such as inculcating kindness and preventing cruelty to animals. Others are the insights of historians and anthropologists, frequently on the basis of comparison with other religious systems. None has proved universally satisfactory, but many have served to bolster the desire of some Jews to observe these challenging restrictions.
The Torah is the source of limitations on what foods from animal sources may be consumed and of the ban on "cooking a kid in its mother's milk." Rabbinic tradition interprets those prohibitions, filling in operative details and setting up further restrictions to provide greater assurance that the Torah's bans are not violated. Over centuries of application and interpretation, these restrictions