About Mutual TLS (mTLS) Authentication
Using Mutual Transport Layer Security (mTLS), clients connect through a TCPS (Secure TCP) database connection using standard TLS 1.2 with a trusted client certificate authority (CA) certificate. With mutual authentication both the client application and Autonomous Database authenticate each other. Autonomous Database uses mTLS authentication by default.
About TLS Authentication
Using Transport Layer Security (TLS), clients connect through a TCPS (Secure TCP) database connection using standard TLS 1.2. A client uses its list of trusted Certificate Authorities (CA)s to validate the server’s CA root certificate. If the issuing CA is trusted, the client verifies that the certificate is authentic. This allows the client and Autonomous Database to establish the encrypted connection before exchanging any messages
