Masa or masa de maíz (English: /ˈmɑːsə/; Spanish pronunciation: [ˈmasa]) is a dough made from ground nixtamalized corn. It is used for making corn tortillas, gorditas, tamales, pupusas, and many other Latin American dishes.
It is dried and powdered into a flour form called harina de maíz or masa harina. Masa is reconstituted by mixing with water before using it in cooking. In Spanish, masa harina translates simply to 'dough flour', and can refer to many other types of dough.
Maize flour or corn flour is a flour ground from dried maize (corn). It is a common staple food, and is ground to coarse, medium, and fine consistencies. Coarsely ground corn flour (meal) is known as cornmeal. When maize flour is made from maize that has been soaked in an alkaline solution, e.g., limewater (a process known as nixtamalization), it is called masa harina (or masa flour), which is used for making tamales and tortillas. Arepas are typically made from corn flour that has not been nixtamalized.
Cornmeal is a meal (coarse flour) ground from dried maize. It is a common staple food and is ground to coarse, medium, and fine consistencies, but it is not as fine as wheat flour can be. In Mexico and Louisiana, very finely ground cornmeal is referred to as corn flour. When fine cornmeal is made from maize that has been soaked in an alkaline solution, e.g., limewater (a process known as nixtamalization), it is called masa harina (or masa flour), which is used for making arepas, tamales, and tortillas. Boiled cornmeal is called polenta in Italy and is also a traditional dish and bread substitute in Romania.