Oracle RAC databases provide the important benefits of connection load balancing and failover.

• Load Balancing of Connections to Oracle RAC Databases
  Services coordinate their sessions by registering their workload, or the amount of work they are currently handling, with the local listener and the SCAN listeners.
• Connection Failover for Oracle RAC Databases
  Oracle RAC provides failover with the node VIP addresses by configuring multiple listeners on multiple nodes to manage client connection requests for the same database service.
• Shared Server Configuration for an Oracle RAC Database
  Standalone Oracle databases perform load balancing by distributing connections among the shared server dispatcher processes.