HOARDING is what happens when people panic and go out and buy ALL the available stock of a few particular items in a store. It spreads the panic to others. This happens during emergency situations. People who HOARD in panic times often have a profit motive and intend to resell their surplus during the panic period. Many just buy out of panic without any real thought as to what they are doing.
PREPPING is buying what you expect to need when there is no external emergency or other time of panic. Preppers are people who ALWAYS have 30 days, 90 day or a year's worth of food and supplies in their home storage. They are the people who ALWAYS replenish what they use as they use it and never create a city, county or national shortage of any particular good because they build their supply as they can afford to do so. PREPPERS plan their purchase as part of their LIFESTYLE and are typically people who also can their own jellies, pickles, sauces, etc. Many just buy and rotate their cans of store bought food, but typically have cases of this type of food at all times.
FWIW, I have lived as a mid-term prepper for years. Typically having 30-45 days of our normal foods on hand at all times. Typically 45+ days of other goods. Sure, we buy toilet paper 2 cases at a time, ditto paper towels, and Kleenex. When we get down to 1 case, we buy 2 more. Cans of tomato products, green beans, etc are bought in case lots. We have several cases of each of those, along with cases of other products including soup mixes, bread mixes, noodles, pasta sauces, etc. We did build our personal supply up over the 6 weeks prior to the panic buying. We have a solid 90 days worth of food (offering us a balanced diet) in storage today. I'm sure we will miss some fresh fruits and vegetables but we do have plenty of winter squash which stores for long periods. We have dozens of fresh eggs, blah blah blah.
Many others here have the SIMILAR inventories of their favorite foods, or of dried foods, or of whatever they choose to have. And they may have much more or somewhat less than we have. This is the type of activity that describes a prepper. I think of the grandparents that lived through the Great Depression and grew their own food, canned and stored their own food, etc. It is that lifestyle that describes a prepper.