Natural hair by definition hasn't been altered by chemical straighteners, including relaxers and texturizers. Straightned hair may still be considered natural because once washed, the texture usually returns to its unaltered state (as long as no heat damage has occurred).
Women may decide to wear their natural hair or protect their natural hair using protective styling. Protective styles include braids, twists, cornrows, scarves, dreadlocks, wigs, extensions and many more. Natural hair empowers women and allows them to be creative.
In terms of natural Black hair, there's no one size fits all when it comes to texture and growth patterns, but in general, natural Black hair usually ranges from wavy to kinky-coily, with a wide range of variation between the two. In fact, texture differences exist not only in families, including siblings, but even on the same head of hair.