BSOFF

What exactly is it, what's the difference?

Thanks in Advance!!!

Kosher was originally created because way back when, before refrigeration and food laws, some food was freaking disgusting. Kosher has a whole bunch of rules. you cannot mix meat with dairy. Fish can go either way. No shellfish at all. No pork. And everything needs to blessed by a rabbi. For instance, let's say you're making kosher hamburgers. The meat may already be kosher because a rabbi declared it as such at the processing plant, but in order to keep the meal kosher, you would have to have the grill blessed. It's very complicated.
The Dairy and Meats get two different kitchens, two different sets of plates, although the Hasidic Jews who live next door just use paper plates for every meal.
There're many more rules, but those are some basics.

certain ingredients can not be combined, and there needs to be 2 full sets of pans; 2 full sets of china.
to make sure that certain ingredients do not EVER combine.

The only part i remember is that orange juice can't mix with milk products.

Oh, yes, some foods have to be inspected by a rabbi at the manufacturing plant, to assure that the food is prepared in a kosher manner.