Any garden-variety produce shelf offers up an embarrassment of leafy green riches, including a good number of the “baby” variety. What exactly does this infantilization of salad mean?

Baby greens are just that—babies. Baby greens like spinach, kale, and arugula are harvested when they’re 15 to 40 days old, as opposed to 45 to 60 days, for a more immature leaf. They’re more tender and, in their youthful state, automatically bite-sized.

From a nutrition perspective, the general consensus is that baby greens and their more mature counterparts are pretty evenly matched. When it comes to spinach, both varieties have supporters who say that one or the other has a higher concentration of vitamins, but no conclusive evidence points in either direction.

With kale, the contrast becomes a little clearer. The tough, bitter leaves of a fully-grown plant can be too much for some eaters, and baby varieties offer a lighter take on both flavor and texture.

Last but not least, there’s arugula, whose baby form is most notably different in its shape. As a youth, arugula is ovular and only gains those leafy limbs in its old age. Every type of green—from romaine to oak leaf to red leaf to butter to mesclun to watercress to endive to mache—can be consumed in its pre-adolescent form, but those varieties might be harder to find. When choosing a bunch or a bag or a shell, just go with your heart (and don’t get iceberg—you need to live a little).

Baby carrots are another matter entirely. Those perfectly shaped, adorable little carrots don’t just pop up from the soil. They are in fact the whittled remains of carrots that are too ugly to be sold in their full and mature state. To make things more confusing, there are tiny carrots, but they look like tiny carrots, not like straightened-out cheese puffs.

Lastly, there are microgreens, the newest wave in youthful vegetation. According to a study in the Journal of Agricultural and Food Chemistry, these seedlings—a mere 14 days young (or younger)—have four to six times more nutrients than their adult counterparts.