There are three coils, which are broken up into a total of 13 turns, 1-5 for the First Coil, 6-9 for Second Coil, and 10-13 for Third Coil. They are the "end" in the sense that finishing all three technically wraps up the 2.x storyline of what happened after the Calamity and all. Heavensward will obviously have it's own plot that adds on to or follows the plot of ARR.