This is a Hebrew word meaning "match". It's also used for foods that abide with the Jewish law. Basically, Jews have really strict principles as it pertains to food stuff. In reality, things like a beef and milk combination are prohibited, there's rabbinical rules and certification for vegetables, fruits etc. Today, kosher foods basically mean ingredients that have been licensed by any kosher company. Here, the check of Kosher Food Items including checking of vat, ovens, pots, packing equipment and other accessories is carried out.
Some Kosher Parameters
Consuming Kosher: Tips to Healthy Living