Other names: white onion, yellow onion, red onion
All members of the alium family onions are one of the most commonly used aromatic vegetables. Onions are classified as dry (yellow, red, white, shallots) or green (scallions, green onions, spring onions). Green onions are simply immature onions.
White onions tend to have a strong flavor and have more heat than yellow onions.
Some onions have been bred for their sweetness lacking the heat typical to most. Examples are Vidalia, Maui, and Walla Walla.
Most onions can be substituted for one another but make sure to adjust the quantity based on the onion used.