Corn Syrup: Corn syrup is extracted from corn starch and is made into glucose. Some recipes call for corn syrup as a sweetener and it is sold in grocery stores, often under the brand name Karo.
High-Fructose Corn Syrup: HFCS goes through additional processing. Three different types of enzymes are added, one after the other, to change the corn starch into first glucose and then into fructose. Additional glucose is then added to THAT to finally create high-fructose corn syrup.
Corn Sugar: Just a new name for High-Fructose Corn Syrup that the Corn Refiner’s Association is trying to get the FDA to approve for food labeling.
So, hopefully not TOO confusing. Corn Syrup – syrup which has undergone an extraction process from corn starch. High-Fructose Corn Syrup – syrup which has been extracted from corn starch, then processed again to turn it into fructose, then has the final whammy of adding yet more glucose to it. Corn Sugar – just another name for HFCS!