Description
 
White onions are vegetables belonging to the allium family.
These bulb-shaped vegetables feature white papery skin and have a mellow, sweet flavor.
White onions have a high water content, making their flesh crisp.
White onions are medium to large in size and are globular in shape with rounded or slightly tapered ends.
The bulb is encased in a bright white, papery, parchment like skin that is flaky, dry, and thin.
These onions are slightly sweeter, a bit milder in taste than yellow onions.
They're a good choice for dicing and serving raw on sandwiches and salads or in fresh salsas.
When onions are cut, says Crosby, their cells are damaged and an enzyme inside them, isoalliin, converts within seconds to a couple of pungent compounds, thiosulfinates and thiosolfonates.
While we prefer yellow for cooking, white for garnishing, and red for pickling, grilling, and everything in between, they're generally interchangeable 
Switching between them won't ruin a dish, even if it slightly alters its flavor or appearance.