OSPF Terminology
ASBR (Autonomous System Boundary Router): a router with an interface connection to an external network or different AS. An external network or different AS means an interface belongs to a different routing protocol e.g. EIGRP. The ASBR is responsible for injecting routing information learned by another routing protocol, into OSPF.
NBMA (Non-BMA): e.g. Frame Relay, X.25, ATM e.t.c. allows for multi access but has no broadcast ability like Ethernet. NBMA networks need special OSPF configuration to work properly.