title: What is the identity property for Azure Storage arm templates for?
body: <p>Looking at the ARM template documentation for Azure Storage accounts there is a field called identity (in API Version: 2018-02-01).</p>
  
  <p>What is identity for in a storage account used for? The documentation is rather vague stating "The identity of the resource" which isn't very helpful.</p>
  
  <p>Deducing what it could be...</p>
  
  <p>In data factory the identity is the service principal or managed service identity being used, but I can't see how an identity is used for a storage account?</p>
  
  <p>Taking a guess...</p>
  
  <p>Is it something to do with Data Lake Store Gen2? </p>
  
  <p>Or perhaps similarly to do with Active Directory authentication (it didn't say in the AD auth preview docs)? Maybe assigning an identity gives it enough information to hook into Active Directory? SQL server takes a similar approach where if you assign an AD admin it enables AD authentication.</p>
  
  <p>Or perhaps to do with syncing across storage accounts? Perhaps giving it an identity for when it's talking to another storage account for using Azure File Sync or something?</p>