Type 2A is wavier than straight hair but not curly. It's a very loosely defined wave. There's no strong S shape. You'll notice an even shorter distance between waves than types 2A and 2B hair, as well as a more defined S shape.
Type 2B wavy texture is not quite straight and not completely curly, with the spectrum of hair ranging from loose loops to coarse, thick S-shaped waves combined with curls. Type 2C hair consists of S-shaped waves mixed with ringlets. These waves and curls begin at the roots, unlike their 2B wave sisters, which start around eye level.