This resting of the dough occurs just after you have mixed your ingredients together. In France the term for this is called an autolyze period. All recipes can take advantage of a resting period, but some recipes will specifically say to let your dough rest after mixing for ten to thirty minutes. This rest allows the starches and the gluten to expand and fully absorb the water, which makes the dough easier to handle and can shorten the time needed to fully knead the dough. This is especially helpful in dough that is very sticky, like ciabatta. The longer you allow your dough to rest, the more water the flour is able to absorb without being mixed by machine. By allowing this to happen your dough will reach full absorption and the results will be stretchy dough that will have a high rise.