AWS Regions: just a cluster of data centers
How to choose an AWS Region? It depends:
- compliance
- proximity
- available services within region - some regions might not have the latest/newest services and features
- pricing
Availability Zones: each region has many availability zones
- each availability zone (AZ) is one or more discrete data centers with redundant power, networking, and connectivity -> why? so that they are isolated from disasters.
- they’re connected with high bandwidth, ultra-low latency networking and this connection is what forms an AWS Region
AWS Points of Presence (Edge Locations): physical locations around the world that cache and deliver content to end users with lower latency - they’re the infrastructure behind CloudFront (AWS’s CDN) and services like Lambda@Edge.
AWS has global services:
- Identity and Access Management (IAM)
- Route 53 (DNS service) - DNS (Domain Name System) translates human-readable domain names (like amazon.com) into IP addresses that computers use to route traffic.
- CloudFront (Content Delivery Network)
- WAF (Web Application Firewall)
"Global" ≠ runs everywhere
“Global” means the service isn’t tied to a specific region, not that it runs inside every region. You don’t select a region when using IAM or Route 53 because they exist outside the region model entirely. Compare that to EC2 or Lambda, where resources in us-east-1 are completely separate from us-west-2.
Most AWS services are Region-scoped: example EC2 (Infra as a service), Elastic Beanstalk (platform as a service), Lambda (function as a service)
Review Questions
What are the four factors for choosing an AWS Region?
A: Compliance (data residency/legal requirements), proximity to users (latency), available services in that region (new services don’t launch everywhere at once), and pricing (which varies by region).
What exactly is an Availability Zone, and why are they isolated?
A: One or more discrete data centers with redundant power, networking, and connectivity. They’re isolated so a disaster in one AZ doesn’t take out the others, but linked by high-bandwidth, ultra-low-latency networking - that linkage is what forms a Region.
What are Points of Presence / Edge Locations for?
A: Physical locations worldwide that cache and deliver content to end users with lower latency. They’re the infrastructure behind CloudFront (AWS’s CDN) and Lambda@Edge.
Which AWS services are global, and what does "global" actually mean?
A: IAM, Route 53, CloudFront, and WAF. “Global” means the service isn’t tied to a specific region - you never select one - not that it runs inside every region. Contrast with EC2 or Lambda, where resources in us-east-1 are entirely separate from us-west-2.
Classify EC2, Elastic Beanstalk, and Lambda by service model.
A: EC2 = Infrastructure as a Service (you manage OS and up), Elastic Beanstalk = Platform as a Service (you hand it code, it manages the platform), Lambda = Function as a Service (you hand it a function, no servers to think about). All three are Region-scoped.