Conche
The conche was invented in the early 19th century by Rodolphe Lindt (yes, that Lindt). Supposedly he accidentally left his grinder on overnight and in the morning found the chocolate wonderfully smooth and mild. He went on to develop a machine that would continuously work the chocolate, refining and smoothing it. Concheing may slightly reduce the size of the particles in chocolate, but it also coats the sugar evenly with fat (cocoa butter), giving the chocolate a much smoother, more homogeneous mouthfeel. The continuous agitation of the mass also mellows the flavor. This is desirable to an extent, ridding the chocolate of funky flavors developed in fermentation. If the process goes on too long, however, distinctiveness will be lost and the chocolate will become bland.