Part of azure governance
Adjacent to azure naming

1. name:value pair
2. identify attribute/metadata for resource
3. Have standards for tags used and values
4. Can enforce through azure policy
   1. deny is scary
   2. better to tell if tag is not there, copy from resource group for example
5. Can be used for search, filter, and billing
6. not inherited but could be copied via policy
   1. should be applied at resources level for better visibility
   2. resources don’t inherit tags from resource group
7. can be applied at resource, resource group or subscription level
   1. not all resources support tagging
8. 202404061425 Azure Cost Management enables inheritance use only for billing usage records

references:

Naming and tagging Guidance and Limits Tag support for resources