Perms the actual term is relaxer are used to chemically straighten black hair. Black people have under-active oil glands in their scalp, so most must add oil to their hair regularly. Caucasians typically have overactive oil glands in their head. Therefore, many white people wash their hair daily to remove excess oils.
White people can achieve many of the same styles as black people.
The styles simply cannot be kept as long. A style might last two weeks with black hair and only two or three days with white hair. White hair tends to grow long and straight. Black hair grows curly and coarse. The textured hair of black people is versatile and flexible, while white hair seems to be stronger and can endure dual processes, such as bleaching and perming, at once.