Onion Scallion

what is the difference between onion, shallots, scallions? Which is the mildest of the three?

Also, Are scallions the same as spring onions/green onions??
Also, Are leeks same as scallions ??

Scallions are the same as spring onions/green onions

Shallot is unique. If I had to compare it to the others, I would say it is a cross between an onion and garlic. Yet mild in flavor. It is my favorite of the list above.

Onion is the strongest, then shallot, LEEK, and then scallion. Of course, there are many onions too. I like Vidalia or Texas Sweets as my favorite onions. They are milder and have a much higher sugar content than eastern onions.

Kershaw Ken Onion Scallion