Is scallion and spring onion the same?? If its not, can anyone kindly explain how can I identify them?

I’m planning to make takoyaki (octopus balls) and I’m quite new to cooking.. I really don’t know the difference between…. different vegetable tthat may look alike,.please help,. thankx,. ^-^

I want scallion seeds for spring planting.?

ohio area so by may 15