What is the difference between Geolocation and Latency Record DNS policy?

Geolocation and latency records are dependent upon geography to one degree or another. The use cases for each, however, are very different. Geolocation records are useful when there is a need to route traffic to a resource based on the specific geographic location the query came from. For example, if the user is in the United States, route them to resources in one of the US-based AWS regions. If they're in South America, route them to the region in Brazil. Also, you need to create a record for the default location to catch any locations that haven't explicitly specified in other records. If a default location is not specified, anyone outside of the locations has been specified will get a nonexistent domain error. When it comes to geolocation, close does not count. Latency records will route traffic based on the network latency between the location of the query and the specific region listed in the resource record. Unlike geography, which is fairly static, network latency changes constantly. This can give some interesting and unexpected results.