Azure Management Groups - Highlights

Paraphrased notes from the official Microsoft documentation -

Azure Management Groups help you organize your resources and Azure subscriptions. Management groups give you enterprise-grade management at scale

Management groups are containers that help you manage access, policy, and compliance across multiple subscriptions. 

Create these containers to build an effective and efficient hierarchy that can be used with Azure Policy and Azure Role Based Access Controls. 

Each management group and subscription can only support one parent.

Management Groups contain one or more subscriptions. 

Inside of Subscriptions are Resource Groups. 

Resource Groups belong to exactly one Subscription. 

A Subscription can have many resource groups, but a resource group may belong to only one subscription. 

Resource groups are containers that hold related resources for an Azure solution.

Azure management groups support Azure role-based access control (Azure RBAC) for all resource accesses and role definitions. These permissions are inherited to child resources that exist in the hierarchy.