I have a line running vertically through my nail. it's like a nail texture because sometimes i clip it from growing out under my nail. what is it?

Nothing too serious: Although you are a young man, these are not uncommon as we age. They may reflect a b vitamin deficiency and might benefit from supplements or dietary changes. If they were across the nail, it would be a different matter. That could be a sign of a serious medical problem for which you'd want to see a doctor. Happily, your ridges run from the base to the tip.