Kosher = food which is allowed. It is the Jewish dietry requirements.

Treyfah = Food which is NOT allowed. 

"These are the animals which you are permitted to eat... anything which has a completely split hoof and chews cud..." (Leviticus 11:2-3)

In leviticus is says:

• all plants are kosher, but not all animals, birds or fish are.
• Animals must also be killed in a special manner and have all the blood removed before the meat ca be eaten by Jews.  

How are animals killed?
Jews may only eat animals and birds that have been killed by Shechitah.
Shechitah is killing the animals by slitting the throat with a very sharp knife.
This has been shows to be painless to the animals, as causing pain to living things is against Jewish law.
The theory is that the sharpened knife cuts the carotid so that the animal loses consciousness before they are able to feel pain.

Kosher	Non-Kosher
Chicken	Pig
Sheep	Rabbit
Cow	Camel
Fish with fins	Eel
Goat	Most Birds

 "You must not cook a young goat in its mother's milk."
Jews who keep kosher kitchens do not eat meat or dairy foods together.
Seperate sets of crockery, cutlery and cooking utensils are used. After eating meat strict Jews will wait several hours before eating dairy products.
Foods which contain either neither meat nor milk, fruit or vegetables, may be eaten with neither meat or vegetables.
The lislt of food wich is allowed is found in the Torah.