title: What is the difference between Azure ACS and Azure AD B2C?
body: <p>I need to add a custom identity provider to Azure B2C and unsure how to do this.</p>
  
  <p>I know this is possible in Azure ACS, but not sure if B2C is just a "prettier" layer on top of ACS.</p>
  
  <p>Can anyone clarify the difference, and perhaps tell me how I can create a custom IDP for a social network not listed in B2C?</p>