A confluence is a meeting, joining, gathering at one point. In geography, a confluence is where two streams or rivers meet, like the confluence of the Missouri and the mighty Mississippi rivers near St. Louis, or the confluence of the Willamette and the Columbia in Portland, Oregon.
Here two patterns are joined: Lazy River and Stream. The patterns use the same stitch, but Lazy River is worked with the yarn held double on large needles, while Stream is worked with small needles, and a single strand of yarn.
While the cowl is worked with two strands of yarn, the mitts are worked with just one strand.