Chapter 10 -> Key Vault ->Is it correct? “The password is never sent to the application itself”

In Chapter 10 -> Key Vault ->Between 1:30-:1:40, you are saying "The password is never sent to the application itself". I am not able to understand this bit. Once the application authenticates itself wouldn’t it be able to retrieve the database password( key) from the key vault? I have seen many examples on the internet where applications are able to retrieve the key in the unencrypted format after successful authentication.