Azure Resource Manager (ARM) Overview

Azure Resource Manager (ARM) is the deployment and management service for Azure. Every interaction with Azure — whether through the portal, CLI, SDKs, or IaC tools — passes through ARM. Understanding ARM is essential for writing effective Infrastructure as Code on Azure.

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What is Azure Resource Manager?

ARM is the control plane for Azure. It receives all API requests, authenticates and authorises them, and then forwards them to the appropriate resource provider (e.g., Microsoft.Compute for VMs, Microsoft.Storage for storage accounts).

Azure Portal
Azure CLI         →  Azure Resource Manager  →  Resource Provider  →  Resource
Bicep / ARM JSON                                  (e.g., Microsoft.Compute)
Terraform

Key Responsibilities

• Authentication and authorisation — validates identity and RBAC permissions
• Request routing — sends requests to the correct resource provider
• Deployment orchestration — manages dependencies and parallel creation
• Template processing — evaluates ARM/Bicep templates and executes deployments
• State tracking — maintains the current state of all Azure resources

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Core Concepts

Resource Groups

A resource group is a logical container that holds related Azure resources. Every resource must belong to exactly one resource group.