Hair density is one of the markers we cosmetologists use to assess hair. Density refers to the number of hair strands per square inch of scalp. It is classified as low (thin), medium, or high (thick).
When we talk wave pattern (or curl pattern), most people think of the hair typing system (i.e. type 3, type 4, etc.). However, in cosmetology, the wave pattern simply refers to the amount of movement in a hair strand. This movement is described as straight, wavy, curly, and overly curly.