Q. What are Tags in Azure?
A. Tags enable key:value pairs to be created and assigned to resources in Azure. These tags can then be used to quickly group and then view resources with the same Tag for easier management. I may create a "Project" key and then different values for the various projects and assign to different resources in Azure. At the time of this writing not all resources support Tags however this will change over time. Using the portal the Tags part can be selected which will open the Tags blade which enables the selection and creation of the key/value pairs. Tags can also be set using the -Tags parameter with supports Azure Set cmdlets.
You can select to Browse the various Tags that exist and then when a key/value pair is selected the resources that have been tagged with that pair can be viewed and managed. It is also possible to pin Tags to the Start board.