Which naming method uses the tnsnames.ora file to store the connect descriptor used by the client while connecting to the database instance from a remote machine?

Host naming method resolves connections using the TCP/IP host name and a default port (1521) without needing a tnsnames.ora file.

The local naming method reads the tnsnames.ora file stored on the client machine to map service names to connect descriptors containing the host, port, and service name required to connect to a remote Oracle database instance. This is the most widely used naming method in Oracle environments. It requires the tnsnames.ora file to be maintained and distributed to each client machine that needs to connect.

External naming method delegates resolution to a third-party naming service such as NIS or NDS, not a local flat file.

Directory naming method uses an LDAP-compliant directory server such as Oracle Internet Directory to store and resolve connect descriptors, not a tnsnames.ora file.