This document discusses using Elastic Load Balancing (ELB) and Auto Scaling together on AWS. ELB distributes traffic across multiple targets like EC2 instances in multiple availability zones and automatically scales to handle changing traffic levels. Auto Scaling automatically scales the number of servers up or down based on load, allowing applications to scale out and in automatically in response to traffic. Using ELB and Auto Scaling together provides benefits like high availability, security, elasticity, flexibility, robust monitoring and auditing for applications on AWS.