When you say OEM or OES replacement part you are implying that, that part is either made by an Original equipment manufacturer, meaning that manufacturer makes parts for Jeep (in our case) but not necessarily the part you are purchasing(at leat when the car was assembled). When you say a part is from the Original Equipment Supplier that implies that the part you are purchasing is the same manufacturer that provided the original part when the vehicle was assembled.

Any other part, such as from the brands you mentioned, are simply aftermarket parts. And those manufactures may state that their parts are OE fit, OE spec, OE finish but that does not imply that they are in fact Original Equipment.

What it also could be is a Mopar part. While they might not have technically been the supplier of your exact part - either the supplier changed during production or it is a service only supplier that has conformed to all of Mopar's standards.

Another reason that dealer parts are more $ is they have gone through all of the original testing for production vs. whatever you get from the auto parts store may have had little to no testing done for validation or quality.

this is true. I personally consider any part made by (or at least marketed by) the manufacture of the vehicle, Chrysler=Mopar, Ford=Motorcraft, GM = AC Delco, to be the OES even if based on my own description this may not be the case. In reality OES is the company that provides the parts that the dealer would buy (Granted it gets a little sketchy with AC Delco since they produce parts for a large number of vehicles as well as different tiers of quality for said parts)