The Azure cloud gives services to thousands of organizations worldwide. Each organization has an isolated environment where it can create resources and configure them to the organization's needs. Inside each of these isolated environments, there can be more levels of separation that make it easier for the organization to manage the resources and their billing. From an Azure standpoint, it doesn't matter whether you represent a large enterprise or whether you are a single developer; the configuration model and billing work the same way, so it's best to understand the concepts that comprise your Azure environment, as shown in the following diagram:

Let's explain the different levels of the Azure environment:

• The root of the Azure environment is the directory (or tenant). This represents the organization that the Azure environment belongs to. Technically, the directory is an Active Directory tenant that holds the user account, roles, and permissions of the given organization.
• Each directory can hold one or more Azure subscriptions. The subscription is the billing container that allows the grouping of expenses that are related to all the resources inside the subscription. For example, an organization might decide that each product will run in a different subscription so that it will be easier to see the expenses related to each product. Alternatively, an organization might decide to give each team a different subscription to run resources related to development activities, and control the budget of each team separately.
• Resources inside a subscription reside inside a resource group. The resource group is a logical container of resources that makes it easier to manage their life cycle together. For example, a product that has a global distribution might be implemented so that all the resources that are deployed to different regions will be grouped together as a resource group. This way, adding or removing a region is easier.

Now that we have covered the basic terms related to accounts and subscriptions, let's delve into the real meat in our environment—resources.