by cvoinescu » Sun Mar 03, 2013 10:19 pm
Burrs cut by way of little raised triangles, much like a rasp or a file, rather than shaving by the continuous, smooth flutes of an endmill. I have no idea how that translates into differences in the finish of the cut, though.
And I third (edit: fourth now, it seems) the endorsement of Drillman1.