What makes a food “kosher”?
Kashrut is the body of Jewish law dealing with what foods we can and cannot eat and how those foods must be prepared and eaten. “Kashrut” comes from the Hebrew root Kaf-Shin-Resh, meaning fit, proper or correct. It is the same root as the more commonly known word “kosher,” which describes food that meets these standards. The word “kosher” can also be used, and often is used, to describe ritual objects that are made in accordance with Jewish law and are fit for ritual use. […] Food that is not kosher is commonly referred to as treif (lit. torn, from the commandment not to eat animals that have been torn by other animals). […] General Rules Although the details of kashrut are extensive, the laws all derive from a few fairly simple, straightforward rules: 1. Certain animals may not be eaten at all. This restriction includes the flesh, organs, eggs and milk of the forbidden animals. 2. Of the animals that may be eaten, the birds and mammals must be killed in accordance with Jewish law.
