Whether done professionally or in the privacy of your own home, chemical hair relaxing can magically alter the basic structure of naturally wavy or  curly hair into a new straighter form.

It is important to note that the treatments known as Japanese hair straightening (Yuko, Liscio, etc.,) are not chemical relaxers.  Instead they are known as chemical straighteners.

The difference between chemical hair straighteners and chemical  hair relaxers (Dark & Lovely) is that straigheners will result in stick straight strands and relaxers will soften and relax.

Chemical straighteners are much stronger than relaxers and can be very harsh and damaging.  Depending on the hair type, texture, condition and prior chemical use, some hair should be chemically relaxed instead of straightened.