OAuth – Internet protocol for authenticating apps and authorizing such apps – to access content on behalf of a specific user.
OAuth – allows SharePoint 2013 and greater versions to
typically authenticate a cloud hosted app – which is calling to a SharePoint
site – from across a network and to establish an identity for the app.
SharePoint 2013 and greater use OAuth to authenticate apps
and establish app identity.
Windows Azure Access Control Services (SCS) is a requirement
for using OAuth.
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