In ASP.Net application which function or element identifies the .aspx or .ascx or .asmx files in .dll

These are the different types of extensions in Dot Net Files. .aspx- Web Form .master - Master Page .ascx - WebUserControl .edmx - Ado Entity data Model .cs - Class file .rpt - CrystalReport .xsd - DataSet1 .ascx - DynamicDataField .htm - HTMLPage .csproj - SilverlightApplication .mdf - Sql Server Database .config - web configuration file .asmx -web services .xml - XML file