Fine hair is hair in which the diameter of each individual strand is fine.
It does not refer to the actual number of hairs on your scalp.
Medium hair will feel thicker in texture than fine hair, both in the individual strands and in terms of the overall volume of hair on your scalp.
Coarse hair will feel rough in texture and it may feel like you have a lot of it. Coarse hair can be straight, e.g. Asian hair, or curly or frizzy, naturally red hair.
African Caribbean hair is the most vulnerable to damage of all hair textures due to its unique structure and specific processing, styling and grooming needs. It requires special care and use of specifically-formulated products in order to look, feel and be at its best.