They're like, spots... Why do they happen? My mom used to tell me that meant that Santa would bring me a lot of presents hahaha.
They're called "leukonychia" . Most of the time they are because of an injury to the base of your nail and only show up about 6 weeks later.
Yeah, someone told me what they were once but I forgot. Though I'm pretty sure that when I don't have them, my nails are healthy.
My mom always told me that it was from not having enough zinc in your diet.