“Recomponentization”
Tim Ahrens, writing for Typekit:
PostScript-based OpenType does not support components, so we need to “recomponentize” our source fonts as they are converted for the web, replacing parts of the contour with their equivalent component. This modification does not affect the appearance of the font, but it can reduce the font size by up to 40%.
Shared by Tim Brown on January 07, 2014.