Babylights are very fine, subtle highlights that are meant to look like the natural hair color of small children (think: virgin hair in the summer), where color is brighter at the crown and the bottom of the hair.

Balayage is a freehand technique where the colour is applied by hand rather than using the traditional foiling / highlighting techniques.

Highlights are the traditional foiling technique used when one wants dimension and brightness coming from the root of the hair. 

Ombré is the gradual blending of one color hue to another, usually moving tints and shades from light to dark.