Tags are key-value pairs that you attach to Azure Cosmos DB resources to better organize them. They are particularly useful when you have many resources of the same type, which in the case of Azure Cosmos DB, is a database. By using tags, customers with hundreds of cloud resources, can easily access and analyze a specific set by filtering on those that contain the same tag. Two of the key advantages of tagging your Cosmos DB are: Grouping and Filtering and Cost allocation.