An Edge location is basically a small setup in different locations that provides low latency connectivity by providing static contents to be available from nearest location of the request. It is basically a Content Delivery Networksetup to make the response faster by providing the response from edge location rather than actual physical location of servers.
Overall what happens is that the content are cached and used by CDN.
Edge locations serve requests for CloudFront and Route 53. CloudFront is a content delivery network, while Route 53 is a DNS service. Requests going to either one of these services will be routed to the nearest edge location automatically allowing low latency no matter where the end user is located.
Image from Amazon AWS