The term which refers to things that are allowed within Judaism and that meet its requirements is kashrut. This mostly relates to food laws.
Those foods which are allowed are kosher and those which are ‘unclean’ or prohibited are treyfah.
The rules are outlined in Deuteronomy 14:4-21:
These are the animals you may eat: the ox, the sheep, the goat, the deer, the gazelle, the roebuck, the wild goat, the ibex, the antelope, and the mountain-sheep. Any animal that divides the hoof and has the hoof cleft in two, and chews the cud, among the animals, you may eat. Yet of those that chew the cud or have the hoof cleft you shall not eat these: the camel, the hare, and the rock badger, because they chew the cud but do not divide the hoof; they are unclean for you. And the pig, because it divides the hoof but does not chew the cud, is unclean for you. You shall not eat their meat, and you shall not touch their carcasses.
Of all that live in water you may eat these: whatever has fins and scales you may eat. And whatever does not have fins and scales you shall not eat; it is unclean for you.
You may eat any clean birds. But these are the ones that you shall not eat: the eagle, the vulture, the osprey, the buzzard, the kite of any kind; every raven of any kind; the ostrich, the nighthawk, the sea gull, the hawk of any kind; the little owl and the great owl, the water hen and the desert owl, the carrion vulture and the cormorant, the stork, the heron of any kind; the hoopoe and the bat. And all winged insects are unclean for you; they shall not be eaten. You may eat any clean winged creature.
You shall not eat anything that dies of itself; you may give it to aliens residing in your towns for them to eat, or you may sell it to a foreigner. For you are a people holy to the Lord your God. You shall not boil a kid in its mother’s milk.
For meat to be kosher, the animal must be slaughtered according to Jewish law. Before cooking the meat must be clean of the animal’s blood, also the sciatic sinew (which runs down the spine to the leg) must be removed.
Along with these restrictions on meat, milk must not be combined with meat, “You shall not boil a kid in its mother’s milk.”