What is remy hair?

Answer 1

Cuticles are a flaky porous layer on the hair. On Remy Hair, the cuticles are all aligned in the same direction. This essentially means that the hair is collected form a single donor. The advantage of remy hair is that they don't tangle easily and hence look much better.

For Non-Remy hair, human hair is collected in piles cheaply and then sorted to create extensions. The direction of cuticles are mixed up. This makes the hair tangle easily and is difficult to maintain.