This image shows interconnecting your on premises data centers with Oracle Cloud.

There are two big boxes, one represent Customer Data Center and the other Oracle Cloud Region. In the customer data center, there are three tiers: Web, Application and Database. Customer Datacenter is connected to DNS of Oracle Cloud Infrastructure via VPN. The image also shows FastConnect, which is a connectivity alternative to using the public internet to connect Customer Datacenter to Oracle Cloud Infrastructure. A load balancer is shown in the corner of Oracle Cloud Region, which connects end customers. Those load balancing instances communicates requests from/to end customers. There is a backbone icon shown under Oracle Cloud Region. The icon represents a physical connection between all the Oracle Cloud Infrastructure regions. It offers private, low-latency connectivity between the regions.