Special folders in ASP.Net

With the release of ASP.NET 2.0, Microsoft has greatly increased the power of ASP.Net by introducing a suite of new features and functionalities.

ASP.Net defines several special folders. When a new Web site is created the App_Data folder is created by default; it can contain a SQL Server 2005 Express Edition database, another database, or an XML data file that will be used in the Web site.

These folders are also data directories.

App_Browsers folder - Contains browser definitions (.browser files) files that ASP.Net uses to identify individual browsers and determine their capabilities. Browser definition files are used to determine the client browser capabilities. These files are often used to help support mobile application.

App_Data folder - App_Data folder is used to store file that can be used as database files (.mdf, .mdb and xml files). The user account that is used to run the application (for example, the local ASPNET account) has permissions to read, write, and create files in this folder. Various ASP.NET application features, such as the providers for membership and roles, as well as the Web Site Administration Tool, are configured to work with the App_Data folder specifically.

Bin folder - Contains compiled assemblies (.dll files), for code that you want to reference in your application, as in earlier versions of Visual Studio. Any classes represented by code in the Bin folder are automatically referenced in your Web site.

App_LocalResources folder - Contains .resx files that are bound to a specific page. You can define multiple .resx files for each page, each .resx file representing a different language or language/culture combination.

App_GlobalResource folder - Like the App_LocalResources folders, but contains .resx files that are not bound to a specific page. Resource values in .resx files in the App_GlobalResource folders can be accessed programmatically from application code.

App_Code folder - Contains source code files. The code is compiled as part of your application and is referenced automatically. The App_Code folder works much like the Bin folder, except that you can put source code in it instead of compiled code. While you are working in Visual Web Developer, the source code in the App_Code folder is compiled dynamically so that IntelliSense can reference any classes defined in the files.

App_Themes folder - Contain sub-folders that each defines a specific theme or look and feel for you Web site. Sub-folders consist of a collection of files (such as .skin, .css and image files) that define the appearance of ASP.Net Web pages and controls.

App_WebReferences folder - Contains files used to create a reference to a Web service (in the same project or external to the project), including .disco, .xsd, .discomap and .wsdl files.

Note: Special folders can be added to a Web site from the Visual Studio menu system. Typically this involves right-clicking the Web Application project and selecting Add ASP.NET folder.