Keywords in AWS infrastructure

Region

• A physical location around the world where we cluster data centers.
• Each consists of a minimum of 3, isolated, and physically separate AZs within a geographic area.

Availability Zone (AZ)

• One or more discrete data centers.
• All traffic between AZs is encrypted.
• AZs are physically separated by a meaningful distance.
• Has independent power, cooling, and physical security.
• Connected via redundant power, ultra-low-latency networks.

Edge locations

• AWS data centers designed to deliver services with the lowest latency possible.
• Usually part of a larger CDN distribution.
• Optimized for caching and delivering content to end-users efficiently.
• Closer to users than Regions or AZs.
• A subset of services which use edge locations:
  • CloudFront.
  • Route 53
  • Web Application Firewall..
  • AWS Shield.

Points of presence (PoP)

• A <table style="display:inline;"><tr><td>physical location</td></tr><tr><td>facility</td></tr><tr><td>data center</td></tr></table> where two or more <table style="display:inline;"><tr><td>networks</td></tr> <tr><td>communication devices</td></tr></table> share a connection.
• AWS has a globally distributed point of presence (PoP) network.
• PoPs host:
  • Amazon CloudFront: a Content Delivery Network (CDN).
  • Amazon Route 53: a public Domain Name System (DNS).
  • Resolution service.
  • AWS Global Accelerator (AGA): an edge networking optimization service.
• Each PoP is isolated from the others.

Edge locations === PoP

They are related concepts in network architecture but not same.

	Edge location	PoP
Function	Content delivery.	Interconnection point for various networks; A central hub.
Infrastructure	Smaller data centers strategically deployed in densely populated areas or key internet exchange points (IXPs).	Vary in complexity, The key requirement is the ability to interconnect different networks efficiently.
Focus	Prioritizes content delivery speed and user experience.	Prioritizes network connectivity and data exchange.
Content Storage	Robust caching servers, storing frequently accessed content like website assets, videos, or static files.	Generally do not store significant amounts of user data or content. Just route data packets efficiently.

In other word:

• PoP: an intersection where data traffic from various networks meets and gets routed.
• Edge Location: a strategically positioned warehouse¹ within a content delivery network, ensuring fast and efficient delivery of cached content to users in a specific region.

Global apps

• Decreased latency => better UX.
• Disaster recovery => better availability (HA).

Different application deployment architecture

	Single region, single AZ	Single region, multi-AZ	Muti-region, active-passive	Muti-region, active-active
High-Availability	✗	✓	✓	✓
Mitigate global latency	✗	✗	✓ Read ✗ Write	✓ Read ✓ Write
Implementaion difficulty	Relatively easy.	Moderate.	Challenging.	Hard.
Visualization

References

• Is Point Of Presence Same As Edge Location?

Footnotes

1. Warehouse here is used metaphorically to describe a server or a data center that stores and manages cached content. ↩