Hey,
Say if you were to fill a chip with some lacquer, you have to sand it flush with the rest of the finish but to do so you would have to use a heavy grit which would scratch the surrounding buffed finish.
To smooth out these new scratches you have to sand a bit wider with a finer grit, so does it just go on like that, wider and wider until you get to a grit fine enough that it all blends in?
Cheers