Due to an overlap of terms and some misperceptions about the ways that Azure services are delivered, terminology is a sticking point even for people who have been working with the technology for some time. The following table provides accurate, but short definitions for the terms related to Azure services. These definitions will be expanded upon in detail throughout the book, so don't worry if you are confused at first:
Term |
Definition |
On-premises |
Means that your data center is hosted and managed at a location your company manages. |
Off-premises |
Means that your data center is hosted and managed in a remote place (for example, hosted and managed outside your company). |
Azure Virtual Machine |
The feature of providing VMs to Azure subscribers. |
Blade |
The window that pops up when you click on one of the Azure services in the Azure portal, such as virtual machines. |
Journey |
A set of blades or chain of selections. For instance, when you select VMs inside the Azure portal, click on an existing VM and then select its settings. |
Resource group |
Provides a logical container for Azure resources (to help manage resources that are often used together). |
Virtual network |
Allows VMs and services that are part of the same virtual network to access each other. However, services outside the virtual network have no way of connecting to services hosted within virtual networks unless you decide to do so. |
Fault domain |
A group of resources that could fail at the same time. For example, they are all running on a single rack, sharing the same power source and physical network switch. |
Upgrade/update domain |
A group of resources that can be updated simultaneously during system upgrades. |
Network security group (NSG) |
Determines the protocols, ports, and who and what can access Azure VMs remotely. |