When I start a new ASP.NET project in Visual Studio, I can create an ASP.NET Web Application or I can create an ASP.NET Web Site.
What is the difference between ASP.
WebSite : It generates app_code folder automatically and if you publish it on the server and after that if you do some changes in any particular file or page than you don't have to do compile all files.
Web Application It generates solutions file automatically which website doesn't generate and if you change in one file than you have to compile full project to reflects its changes.