# Regions, Zones and the Global Network — Google Cloud Platform

Source: https://www.skillbyai.com/en/gcp/f-global

> Explain regions, zones and multi-region locations, and choose where a workload runs.

## Zonal, regional, multi-regional and global resources

**Google Cloud** runs in **regions** (such as `asia-south1` in Mumbai and `asia-south2` in Delhi), and each region has three or more **zones** (`asia-south1-a`, `-b`, `-c`): isolated failure domains with separate power and networking. A key idea in Google Cloud is the **scope of each resource**. A Compute Engine VM or persistent disk is **zonal**; a regional managed instance group, a Cloud Run service or a regional persistent disk is **regional**; Cloud Storage buckets can be **dual-region** or **multi-region**; and some resources are **global**, such as VPC networks, firewall rules, global load balancers and IAM policies. Traffic between regions travels on Google's private backbone rather than the public internet. When you choose a location, weigh user latency, data-residency rules, service and machine-type availability, and price, which varies by region.

## Zones inside regions on one backbone

Regions contain zones; Google's backbone connects regions, and some resources span them all.

![Three region shapes connected by a thick backbone line, each region holding three small zone squares, with a faint global ring around everything.](assets/figures/gcp/section-1-map.svg) — Figure 1.1 — Zones, regions and global resources.

## Exploring locations with gcloud

The `gcloud` CLI is the main command-line tool; it also sets defaults so you do not repeat `--region` everywhere.

```bash
gcloud auth login
gcloud config set project shop-dev-123456

gcloud compute regions list --format="value(name)"
gcloud compute zones list --filter="region:asia-south1"

# sensible defaults for this configuration
gcloud config set compute/region asia-south1
gcloud config set run/region asia-south1
```

## Zonal means one zone can take you down

A single VM with a zonal disk does not survive a zone outage. For production, use regional managed instance groups, regional disks or regional services such as Cloud Run and Cloud SQL high availability.

**Quiz:** Which of these is a global resource in Google Cloud?

- [x] A VPC network
- [ ] A Compute Engine VM
- [ ] A zonal persistent disk
- [ ] A single zone

*Answer:* A VPC network. VPC networks are global; their subnets are regional and VMs are zonal.