What is totally stub area in OSPF?
If we want to reduce the size of the routing table in all the routers in an area, then we can configure the area as a stub or totally stub area. For more information about stub area, please check the link.
When we configure an area as totally stub area, LSA 5 and LSA 4 are not advertised into that area. All LSA 3 are also not advertised except the default route (LSA 3). This default route is originated by the ABR even though it does not have a default route.