I am new in sharepoint can anyone suggest Difference between asp.net master pages and SharePoint master pages?
SharePoint is designed on the concept of Master Pages. Almost all of the out of the box ASP.NET pages in SharePoint inherit from a Master Page. Thus, if you want to customize the look and feel of all the SharePoint pages, you can do this by customizing Master Pages. This allows for a centralized place to make customizations (instead of modifying every Web page in the entire SharePoint system).
You can go through following link for more information,