Modern link-state routing protocols are designed to minimize the effects on memory, CPU, and bandwidth. The use and configuration of multiple areas can reduce the size of the link-state databases. Multiple areas can also limit the amount of link-state information flooding in a routing domain and send LSPs only to those routers that need them. When there is a change in the topology, only those routers in the affected area receive the LSP and run the SPF algorithm. This can help isolate an unstable link to a specific area in the routing domain.
For example, in the figure, there are three separate routing domains: area 1, area 0, and area 51. If a network in area 51 goes down, the LSP with the information about this downed link is only flooded to other routers in that area. Only those routers in area 51 need to update their link-state databases, rerun the SPF algorithm, create a new SPF tree, and update their routing tables. Routers in other areas learn that this route is down, but this is done with a type of LSP that does not cause them to rerun their SPF algorithm. Routers in other areas can update their routing tables directly.