The aim with both pastries is to form thin layers of fat between very thin layers of dough to produce a pastry which rises well. Puff pastry is the richest and lightest of the two, and usually uses equal quantities of fat to flour. Some of the fat is rubbed into the flour, as in shortcrust pastry, but then the rest is added in a single piece and distributed through the dough by a lengthy process of rolling and folding, which builds up the number of layers and the subsequent lightness of the pastry.
If the butter is cut into pieces instead of formed into a compact slab, and if the folding process is shortened, the result is flaky pastry, which does not rise quite as effectively as puff pastry. Rough puff pastry uses less fat then puff pastry and is easier to make. The fat is cut into small pieces and added all at once to the flour. Rough puff pastry also needs less rolling and folding.
** Asian Desserts