This system is a fairly recent development created by Andre Walker who was Oprah's personal hair stylist. The general classifications are straight, wavy, curly, or coiled and each of these has three subdivisions based on tightness or looseness of the curl. It is quite normal to have hair that is more than one subdivision.
The amount of curl in your hair is determined by the follicle of your hair. Its shape is what makes the curl and that is determined by genetics although it can be changed via heat or chemical. Lets start with type 1 which is straight hair. The individual strands may be fine or course but they have absolutely no curl at all. This type of hair tends to run oily and it is recommended you look for products that will not add extra oil or weight to your hair. In addition, use a dry shampoo rather than washing it every day.
Next, is type 2 which is wavy which means the hair has a wavy that looks gently tousled from eye level length down to the end but from the roots to eye level, the hair is relatively straight. This hair can be divided into 2A which is flat from the roots to eye level and then wavy from that point down. The wave is gentle and nice. The second is 2B which also has waves from eye level down to the ends but the curls have more of an S shape. This type of hair looks great done in a balayage style. The last, 2C is hair that has more of an S shape from eye level down.
Then we have type 3 or curly hair which also has three subdivisions. The first is 3A in which the S shaped curls form loose loops and look more like loose ringlets. Unfortunately, should you decide to brush your hair, the curls will turn into a frizzy mess. Using curl defining products is recommended to keep the curls looking nice and it is recommended you do not put your hair in a ponytail or your hair will lose the curls.
Of course type 3B has larger curls. The circumference of the 3A curls are about the same size as a dinner candle while the circumference of 3B curls are about the same size as a large sharpie. It is recommended one provide moisture to keep the curl in the hair from roots to ends. The 3C curls are curliest of this group with a circumference equal to that of a drinking straw so these curls are the tightest. It is recommended you use leave in conditioner and only use fingers to comb it otherwise you could turn your curls into frizz.
The last type is type 4 or coiled hair. Hair classified as 4A has extremely tight S-shaped curls that will wrap around a chop stick and it is extremely delicate. It is very dry and needs a lot of moisture. Choose a wash and wear style so it remains healthy. The curls found in type 4B hair has a zig-zag pattern but again, use leave in conditioner. One way to fix this type of hair is to divide it into four sections and place curling creme in each section before wrapping each section around your index finger.
The final subtype of hair is 4C which has the tightest curls and are the most fragile. Unfortunately, it is easy to break or damage this type of curl if you comb it too often or too roughly. Use plenty of moisturizers on your hair and some people only use a condition, never a shampoo on it.
Figure out what type of hair you have and it makes it easier to keep your hair healthy and under control. let me know what you think, I'd love to hear. Have a great weekend.