If you are an individual who has an interest in MREs, then there's a variety of things that might interest you about this special type of food. A number of consumers love MREs since they make for easy eating when out in the wild hiking, hunting, or camping. Another segment of the market is represented by consumers who like to have an emergency stockpile of food around for situations and times where there might not be power or water. You likely fall into one of these two groups, and possibly even both. Regardless, if you have experience shopping for MREs, then you already are aware of the fact that MREs on the market come in both civilian and military grades.
MRE meals that are considered or labeled as military grade do not sport the variety of flavors and foods that their civilian grade counterparts do, but the military ones are often higher in nutrition and have a longer shelf life. They're also more likely to present a 'total' meal featuring an entree, a spread, a bread item, a snack, a beverage, and a dessert. You'll also likely find an accessory kit which includes a spoon, a condiment kit, a napkin, and instant coffee featuring nondairy creamer. An FRH, or flameless ration heater, is a common option.
On the other hand, civilian grade MRE meals typically mix and match various items and components, so you can't rely on receiving a 'total' meal all in a single packet. So, if you're just compiling an emergency stash, then the military grade variants prove the better choice. Unfortunately, things get complicated if you do this.
Are you a purist? If so, then you might prefer the specific units that military branches use, either from surplus supplies or just buying from the same supply manufacturers that the United States Department of Defense buys from. Regrettably, MREs that say that they are military grade are not always actually military. Some units are made at military standards and quality levels but only sold to civilians. Pragmatic consumers aren't going to care, but an enthusiast is likely to care enough to dig into the fine print and research the specific product line.