How Latency records policy offers a better approach than the Geolocation record policy.
Latency records offer a way to improve the client experience by sending the client to the resource with the lowest network latency. Unlike geolocation records, when it comes to latency records, being geographically close to a resource does count. As a rule, the closer two sites are geographical, the less network latency there is between them. Consider the two latency records, the first record uses a latency routing policy that lists us-east-1 which is in Virginia (in East coast) as the AWS region. This record points to web-1-east as its alias target. The next record uses a latency routing policy that lists us-west-1 as the AWS region, that region is in California, on the West Coast. This record points to web1-west as its target. Suppose that DNS server, sitting in South Carolina, tries to resolve www.example.host, it would get the record with the us-east-1 region, which points to web1-east due to low latency.