same thing here too, scallions are considered the same as green onions. but my neighbors grow an onion that is half way between scallion, which they call spring onions, and regular onions. it looks like a fat bulbed scallion, a little smaller than a golf ball, which they call a green onion.
for scallions, depending on the dish you can use all of it, or just the white part. sometimes the green part can be a little bitter, in which case you may not want to eat it. otherwise, i always use the whole scallion.
btw, if you get the chance, buy or make scallion kimchi. it rocks!!!
A true lover of nature does not despair now that his mistress has turned a colder cheek.