Oracle Access Manager OAM Authentication

Oracle has published below diagram describing Authentication with OAM. On the left side is the User, who is trying to access a resource which is protected by the OAM.

Note: OAM and WebGate work together, where WebGate can be said to be an agent for OAM. The diagram is valid from 11gR2 versions but later 12c version retains the same architecture.

OAM Authentication steps