What are 'tags' referring to in the Azure API app settings?

I'm not sure what 'tags' are referring too in the API App settings, I wondered if I might be able to set App Settings anywhere and if this was that ability but I am not sure and cannot find any documentation on this. Any help is much appreciated.

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Solution

Azure Resource Manager allows you to use tags to organize all your Azure resources. This allows you to group and filter resources in the Preview Portal, and will also allow you to slice and dice your usage and billing information by tag.

https://azure.microsoft.com/en-us/documentation/articles/resource-group-using-tags/