title: Azure: Service Principal ID vs Application ID
body: <p><a href="https://docs.microsoft.com/en-us/azure/active-directory/develop/app-objects-and-service-principals#application-and-service-principal-relationship" rel="noreferrer">According to this documentation</a>: Application and Service principal are clearly two different things. Application is the global identity and Service principal
  is per Tenant/AAD</p>
  
  <p>But <a href="https://docs.microsoft.com/en-us/azure/active-directory/develop/howto-create-service-principal-portal" rel="noreferrer">This Documentation</a> and <a href="https://serverfault.com/questions/896673/how-to-find-the-service-principal-assigned-to-a-newly-created-aks-cluster">This Stack Overflow Question</a>  suggest they are the same.</p>
  
  <p>To make it more confusing, When I used the Graph API (from the first reference) and queried by my application name:</p>
  
  <pre><code>https://graph.windows.net/&lt;tenantName&gt;/applications?api-version=1.6&amp;$filter=displayName eq '&lt;Apllication Name&gt;'
  </code></pre>
  
  <p>I see a object Id, an Application ID (which I thought were the same), but no service principal ID in the Json </p>
  
  <p>What is the relationship between AppID and ServicePrincipalID (and ClientID, ObjectID) ?
  Thanks.</p>