In the United States, Canada and a few other countries, maize and corn are one in the same, a tall grain plant with seeds, called "kernels," often used for cooking. Although maize is the proper name for the plant itself, the word "corn" more accurately refers to whatever common local grain is most harvested for its edible seeds. That means maize in most of North America but otherwise varies by region.
The word "maize" comes from the original name of the plant given by the Taino, one of the indigenous peoples of the Bahamas and Antilles islands. In British English, the word "corn," simply means cereal.