What is inside a project?

Since ASP.NET 2.0 does not have the concept of “projects”, the below section is applicable only for non-website applications.
As we mentioned earlier, a project contains a set of related files. How does project look like outside Visual Studio?
In simple words, a project is an xml file. When you create a project using Visual Studio or VWD, it creates an XML file. The project file contains some information like version number etc and the list of all files part of the project.
You can use notepad or any other text editor to open the project file and view the contents. When you open a project file using notepad, it will show the contents of the xml file.
But when a project file is opened using Visual Studio, it knows that it need to do something more than just showing the contents of the file. Visual Studio (or, VWD)t will read the contents of the xml file and display the list of files included within the project, organized as a tree view.
You can click on the files in Visual Studio and open the file. Also, you can use the “build” option to compile all the files in the project.
If you are using notepad to create all files and do not have Visual Studio, you can still develop .NET applications. You have use windows explorer to select and open any source file and edit. You will have to use command prompt to compile each and every file separately. But this will be a painfull and time consuming process. Instead, if you are using Visual Studio (or VWD), all your related files will be organized into one project and you can easily open, edit, save or build all files from Visual Studio. All source files in one project will be compiled into one DLL or EXE.