> For the complete documentation index, see [llms.txt](https://notebook.iuriioapps.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://notebook.iuriioapps.com/cloud/azure/organization-and-management.md).
# Organization & Management
### Regions and Availability Zones
* **Region** - a group of data centers in a single geographic location. For example, "Central US", "South India", etc. Provides high availability and fault tolerance. Deployments are closer (geographically) to your end users. Defends against regional outages.
* **Availability Zone** - one of several unique locations in a region. There might be one or more individual data centers per zone. Each zone is self-contained (power, cooling, networking, etc). Availability zone deployments are mainly for fault tolerance, protecting against a single point of failure.
### Azure Resource Manager (ARM)
Centralized management layer - no matter how you connect to Azure, all requests go through ARM to provide access control
* Web portal
* Command-line interface (CLI)
* Application Access
* Access Control (authentication)
### Tenancy
* Everything starts with a single **Azure Tenant**. Single organization instance of Azure AD.
* Each Tenant can have one or more **Management Groups**. Management group serves as a grouping component (optional), central management of multiple subscriptions.
* Each Management Group can have one or more **Subscriptions**. Subscription is a primary billing and access isolation boundary, each subscription has its own billing agreement.
* Each Subscription can have one or more **Resource Groups**. All Azure resources are created in Resource Groups, serve as a container for resources with same purpose/lifecycle.
* Each Resource Group can contain one or more **Resources** (VMs, DBs, Functions, etc).