Authentication overview for SharePoint

Authentication overview for SharePoint

I found  a very good guide from MS that explains how users can authenticate SharePoint. It clearly explains authentication mechanisms of SharePoint.

SharePoint 2013:

 http://technet.microsoft.com/en-us/library/jj219571%28v=office.15%29.aspx

SharePoint 2010: 

http://technet.microsoft.com/en-us/library/cc288475%28v=office.14%29.aspx

 

I hope the above information will help you to resolve the issue, in case of any queries/questions regarding the above mentioned information then please let me know. I would be more than happy to help you as well as resolves your issues, Thank you.