When you choose the "Certified Organic" label, it means that an item is GMO-free, it also means that 95% or more of the product's contents are organic, free from chemical dyes, grown without the use of synthetic pesticides, herbicides, and chemical fertilizers, and must not be processed using industrial solvents, or irradiation. Studies have also indicated that organically grown food is higher in nutrients and lower in heavy meals.
In Non-GMO products, the only guarantee is that GMOs are not allowed. A Non-GMO label prohibits the use of certain herbicides that contain GMOs, but it does not require or stipulate that "Non-GMO" products must be grown organically. Additionally, only products labeled "Non-GMO Project Verified" verifies that a product doesn't contain genetically modified ingredients (or technically less than 0.9% GMOs).