Masa harina is the corn flour used by Latin Americans to make corn tortillas. If you live in the west or southwest US it's available in regular grocery stores. Maseca is a brand that's widely available. If you try baking with masa harina it gives the finished goods a very pronounced corn tortilla flavor, which I don't care for since I associate that flavor with corn tortillas and nothing else.
Producing masa harina involves a process called nixtamalization. What I don't understand is that hominy is also produced by using nixtamalization but hominy and hominy grits don't have that characteristic corn tortilla flavor that you get with masa harina. Does anyone know why?
Here are some relevant links: