After the short call-and-response prayers of the Suffrages, the worshiper comes to a set of collects: first the Collect of the Day, then at least one from a list of seven, and a Prayer for Mission. The devotional aim is to move from shorter to longer prayers; where the Suffrages summarize, the Collects dig deeper.
So, traditionally, there are three Collects in a row: the Collect of the Day followed by two set Collects according to the time of day (in the Morning it’s for Peace and for Grace, as the rubrics note). By 1662 additional prayers were added to these, though not required in the rubrics. In the 1979 and 2019 Prayer Books those two Collects got expanded to the seven choices we have today, plus a choice from three Prayers for Mission.