If you walk into your neighborhood grocery store, you’ll see some variety, but the difference lies primarily in appearance versus taste.
There are different types of flat beans, and their shape affects how you cook them and how well they’ll soak in the flavors of other foods.
Romano beans are most likely the most well-known of all flat beans. These are usually wide and full of bright flavor.
Technically, this isn't a bean, but snow peas fit the bill when you need something flat to cook with. Also, this is an easy substitute for any pole bean when you can’t find Romano beans.
Fava beans are also called broad beans because of their shape. The side of fava beans is long and flat, with rounded ends on both sides.