The difference between hoarding and stockpiling is when you do it. Hoarding is when you buy up stuff that is in short supply, so that when you get yours, someone else gets none. Stockpiling (preparing) is when you buy far enough in advance of the shortage so that when you get yours, there is no shortage and everyone else can get some. Profiteering is when you sell your stockpile at greatly increased prices. Selling neighbor some diesel fuel or water is not profiteering when your price is about what you paid for it or at perhaps five percent markup for handling costs.