Kettle corn is known to be the type of corn that can be received from the normal popping corn. Popcorn and kettle corn will look the same. The only difference will be how they would be popped. From the name of kettle corn, you can already guess that this has been popped from a kettle. The large, iron kettle will usually be oiled enough so that the different corn kernels can pop.
After the popcorn has already been popped, that is the time when all the extra flavors will be added. For kettle corn, it will always come with a bit of sugar to give it the sweet and salty taste that people love. Popcorn can be popped normally and would be flavored with salt and butter.