Traffic flow simplifies the process of creating and maintaining records in large and complex configurations. This is useful when you have a group of resources that perform the same operation, such as a fleet of web servers for the same domain.  

The traffic flow visual editor lets you create complex sets of records and see the relationships among them. You can combine multiple routing policies and health checks in a single configuration. Each configuration is called a traffic policy and it’s automatically versioned so you don’t have to start all over again when your configuration changes. Old versions of traffic policies continue to be available until you delete them. 

A traffic policy can define hundreds of records. Traffic flow creates all those records automatically when you create a policy record.  You create policy records to associate traffic policies with a domain or subdomain name records.  The traffic policy record appears in the list of records for the hosted zone. You can use the same traffic policy to create records in multiple public-hosted zones.  This is useful when you’re using the same hosts for multiple domains.  

Please note that the Geo-proximity routing policy is available only if you use traffic flow.