Who is this article for?

Administrators who want to learn to 

No elevated permissions are required.

This article explains how authentication works when accessing SharePoint through integrated applications.

1. Credentials

Authentication with SharePoint uses the Windows username, password, and domain of the currently logged-in user.

When accessing SharePoint as part of a cloud-based platform environment, claims-based authentication is used along with the credentials provided by the user when accessing a location.

The credentials of the current user can be overridden to provide alternate credentials when accessing SharePoint.