This brief description is from Wilson's site. I like it so much I've shamelessly copied it word for word.
At Wilsons we’re all about offering choice to our customers and the very best nutrition for their dog.
Raw food is as minimally processed and natural as wet dog food can get. Our raw dog food manufacturing includes no heating, bulking or complicated processes which can destroy all of the goodness and benefits.
Our recipes contain no colouring or preservatives. Our Premium recipes have added vegetables, herbs, and vitamins, making them a nutritionally complete meal with no need to add anything to it.
With the right amount of protein and fat with no fillers, digestion is quicker and easier. Moreover, raw fed dogs tend to have healthier weight, better skin, breath, and reduced shedding.