There are basically three different types of hair, curly, straight and wavy.
Most of the time hair texture and color is inherited. Sometimes hormones and medication can change hair.
Today one can change curly hair to straight and straight to curly. This can be done temporary or permanent.
Permanent only means the hair that has grown from your head and not the hair that will grow in the future this means that the new growth will not be affected by what ever chemical you introduced to the hair.
Hair texture is measured by the degree of which one's hair is either fine or coarse, which in turn varies according to the diameter of each individual hair. There are usually four major types of hair texture: fine, medium, coarse and wiry. Within the four texture ranges hair can also be thin, medium or thick density and it can be straight, curly, wavy or kinky.