This document provides an overview of Oracle Real Application Clusters (RAC) architecture. It discusses how RAC allows for high availability and scalability of Oracle databases across multiple nodes. The key benefits of RAC include improved throughput, high availability even if a node fails, improved response times, and transparency. It also provides an example of how workload is managed in a RAC system when a node fails, comparing RAC to alternative technologies like SQL Server, and discusses real-world examples and cost savings of implementing RAC.