What would be the common layers in an n- tier architecture based web application?

Common layers in an n- tier architecturePresentation GUI: Look & Feel ,Html, aspx file, JavaScript, window forms etc. Controller- Work flow layer: aspx.cs file, means event handlers and Data binding with controls etc. Business Logic: where we implement business rules like add book, search library etc. Data Access: SQLHelper.cs like create connection, get DataSet, Execute Query etc. Physical Data: