As in life, onions also perform their job better if they're used where they're meant to be. Here are the types of onions and their uses.
Content table
1. Yellow onion
With a strong flavor, it's the most common. Ideal for accompanying meats or as a base for sauces and soups, sautéed.
2. Sweet onion
Similar to the yellow onion, but slightly sweeter. Ideal for frying, making onion soup, or caramelized onions .
3. White onion
Less common than yellow, it's stronger and crispier due to its high water content. Ideal for light frying (with vegetables, for example) and raw sauces.
4. Red onion

It's the easiest to eat raw... and the prettiest! It's crunchy and slightly sweet. Ideal for slicing into salads, guacamole , pickles, sandwiches, or lightly roasted.
5. Shallot
Not technically an onion, it has a flavor somewhere between red onion and garlic, and grows similarly to the latter (I LOVE them). Ideal for vinaigrettes, dressings, or in warm vinegar sauces (like the sauce in this recipe for pork in vinegar ).
6. Spring onion, spring onion or green onion
It's physically distinct because it doesn't form bulbs. It's eaten when it's still fresh. Ideal for salads and stir-fries. Also for adding the finishing touch to dishes. If you're in Spain, I'll tell you: the green part is the best! For me, it's what has the most character in this onion. At the greengrocer's, they discard this part, so when you ask for it, they'll give it to you for free.
SOURCES: buzzfeed , cocinayvino.
For the empanada mince, which onion is better?
In Costa Rica we call spring onions that have green leaves chives.
In Spain, spring onions are rounder at the bottom (yes, they "bulb") and then have a small stem and those green parts on top. The one in photo 6 looks like what's called a leek here.
What about calçots, girl?
And what do you think about leeks? Onion and leek tarts are delicious.
I loved the note!
Paulina, the last photo isn't a green onion...it's a leek...