Edamame are just soybeans, green fresh soybeans. They can come in a pod, then you boil in salted water for 5-7 minutes, then you deshell and eat. SO YUMMEH! Use them in salads, just snacking, in rice dishes, places you'd use beans.
Sometimes you find them in the fresh food refrigerated section - already shelled. Usually in the frozen veg section. Buy the ones IN pods...frozen and shelled are always gross and slimy.
You can also buy them canned. You drain, dry, and roast in the oven until crunchy little delights. Like...a roasted peanut. I do mine in olive oil and salt. Various recipes around for roasted soybeans.