Region

A region in cloud computing is a geographic area in which a cloud provider operates a cluster of data centres. Regions are independent of each other: an outage in one does not affect another, services in one cannot directly reach storage in another, and costs differ across regions. Region selection is one of the first architectural decisions for any cloud deployment.

Why regions exist

• Latency. Closer regions give faster responses to nearby users.
• Data sovereignty. Regulations may require data to remain in a specific country or block (GDPR, India's data protection rules, China's separate clouds).
• Disaster resilience. Running in multiple regions survives the loss of an entire region.
• Service availability. Not every service launches in every region; newer regions may lag.

How regions are organized

Each region contains multiple availability zones (typically 3 to 6), which are isolated data centres connected by low-latency private fibre. A region serves as a fault domain at the largest scale; AZs provide an additional fault boundary inside the region.

Cross-region patterns

• Active-passive (DR). One primary region serves traffic; a secondary region is kept warm for failover.
• Active-active. Multiple regions serve traffic simultaneously, typically with global load balancing in front (Route 53, Cloudflare, Global Accelerator).
• Region-pinned data. Some data legally must stay in a specific region.