Alaffia defines the three type of curls in the following way, taken from their website:
In wavy hair, the wave or curl forms a gentle "S" pattern throughout the hair. Wavy hair yields to gravity, hanging down and staying relatively close to the head.
Kinky hair is very tightly curled, with a clearly visible spiral pattern that can have rounded curves ("S" pattern), or more angled curves ("Z") pattern. Kinky hair can easily tangle, since the coils interlock together. Because of this, breakage will occur if care is not taken when detangling.
Curly hair is all curls in between wavy and kinky. This covers a large range of curl diameter, but in all cases, the curls are well defined, springy with a well-defined "S" pattern, and ranges from big, loose curls to bouncy, tight corkscrew curls.
For more information about the different types of curls & Alaffia's suggested care instructions, please visit the following web page: http://www.beautifulcurls.com/store/pc/curlTypes.asp?ilink=2&idcategory=1000#textures