Why Are Vellus Hairs Normal at the Hairline?

Hi doctor, I just have two questions. Why in the beginning of normal hairlines the existence of miniaturized hairs and vellus hairs is normal?

And the second question is that how can you distinguish them in your hairline?

The very frontal leading edge of the hairline has more vellus hairs per square centimeter than other parts of the scalp. If you get a video microscope (see here), you can then study them and maybe understand what is growing out on your head better. It’s normal, because that is the way it is. It’s genetics. It’s a transition area from nothingness to a head of hair. Vellus hairs are usually short while miniaturized hairs can grow long, so they usually can be distinguished from each other that way.