OSPF Area Design Advantages

erickafabiana

In the Cisco Press book 200-105 Wendell Odom speaks of advantages of OSPF Area Designs. In one of the bulletins he says

- Changes in the network (for example, links failing and recovering) require SPF calculations only on routers connected to the area where the link changed state, reducing the number of routers that must rerun SPF.

Im assuming that statement ^ refers to a redundant link within that Specific Area ^. For the routers to recalculate SPF ?

Also the routers in different do not need to recalculate but still get notified that the link went down ?