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?

The tnsnames.ora file is a configuration file that contains network service names mapped to connect descriptors for the local naming method, or net service names mapped to listener protocol addresses. A net service name is an alias mapped to a database network address contained in a connect descriptor.

Configuring the Local Naming Method
The local naming method adds net service names to the tnsnames.ora file. Each net service name maps to a connect descriptor.
Example 8-2 shows the net service name sales mapped to the connect descriptor contained in DESCRIPTION. The DESCRIPTION section contains the protocol address and identifies the destination database service. In this example, the protocol is TCP/IP and the port is 1521.

https://docs.oracle.com/cd/B13789_01/network.101/b10775/naming.htm#i448068