What are AWS Regions and Availability Zones?
Answer
AWS infrastructure is organized into a global hierarchy: Regions: a geographic area with multiple, isolated locations (Availability Zones). Each region is completely independent — no automatic replication between regions. Choose a region based on: latency (closest to users), compliance (data must stay in specific country), service availability (not all services in all regions), pricing (varies by region). Examples: us-east-1 (N. Virginia — most services, lowest price), eu-west-1 (Ireland), ap-southeast-1 (Singapore). 32 launched regions worldwide (2024). Availability Zones (AZs): one or more discrete data centers within a region, each with redundant power, networking, and connectivity. Physically separated by meaningful distance (miles apart) but connected with high-bandwidth, low-latency fiber. AZs within a region are identified by a letter suffix: us-east-1a, us-east-1b, us-east-1c. Each region has 2-6 AZs. Design principle: deploy across multiple AZs for high availability — if one AZ fails, others continue serving. Local Zones: extension of an AWS Region to more geographic locations — low-latency access to AWS services for specific metro areas. Wavelength Zones: AWS infrastructure embedded within telecom networks for ultra-low latency to 5G mobile devices. AWS Outposts: AWS infrastructure, services, APIs, and tools running on-premises — hybrid cloud, low-latency local processing. Edge Locations: CloudFront and Route 53 PoPs — 450+ globally for caching and DNS. Not full regions — no compute or storage services (just CDN and DNS).