The figure has two sections. On the left are systems that have security objects like TDE master keys, keystores, and other credential files to upload to Key Vault. On the right is Key Vault.
Reading right to left:
On the right is Key Vault in a high availability deployment with a Primary and Standby server.
On the left reading from the top:
Is an Oracle middleware configuration connected to an Oracle database.
From the middleware and database servers, the application encryption, network encryption, secure external password store (SEPS), and features such as TDE, Data Pump, RMAN, Oracle Secure Backup, and Automatic Storage Management Cluster File System communicate to Key Vault, to upload or download Oracle wallets over a TLS connection.