Straight
Not much to say about this style except that it is straight. No curls, but if you wet it, it becomes wavy.

Wavy
A wavy wig has hair that has flowing waves in it. Not as curly as a curly wig, not as straight as a straight wig... wavy wigs tend to give a more natural and less heavily-styled look.

Curly
A curly look wig is usually a curly style wig designed to look wet, as if a sheen spray had been applied.

Sharon