Amazon Route 53 (Route 53) is part of Amazon.com's cloud computing platform, Amazon Web Services (AWS). Route 53 provides a scalable and highly available Domain Name System (DNS). The name is a reference to TCP or UDP port 53, where DNS server requests are addressed. In addition to being able to route users to various AWS services, including EC2 instances, Route 53 also enables AWS customers to route users to non-AWS infrastructure. Route 53's servers are distributed throughout the world. Amazon Route 53 supports full, end-to-end DNS resolution over IPv6. Recursive DNS resolvers on IPv6 networks can use either IPv4 or IPv6 transport to send DNS queries to Amazon Route 53.
One of the key features of Route 53 is programmatic access to the service that allows customers to modify DNS records via web service calls. Combined with other features in AWS, this allows a developer to programmatically bring up a machine and point to components that have been created via other service calls such as those to create new S3 buckets or EC2 instances.
AWS supposedly named the service Route 53 because all DNS requests are handled through port 53, and the "route" piece resembles the historic "Route 66" of the USA. And Route is basically for routing any traffic to Amazon DNS.