Region: A region is a geograpical area. Each region consists of 2 or more Availability Zones(AZs)
Availablity Zone (AZ): An Availability Zone (AZ) is one or more discrete data centers with redundant power, networking, and connectivity in an AWS Region.
Edge Location: Edge location are endpoints for AWS which are used for caching content. Typically this consists of CloudFront Amazon Content Delivery Network (CDN).