A C# program is built from source files, which are text files containing the code you write. Source code files are named with the .cs extension. The HelloWorld.cs file you created in Chapter 1 is an example.
A typical Visual Studio 2005 application can have a number of other files (such as assembly information files, references, icons, data connections, and more). Visual Studio 2005 organizes these files into a container called a project.
Figure 2-1. Visual Studio start page
Visual Studio 2005 provides two types of containers for your source code, folders, files, and related material: the project and the solution. A project is a set of files that work together to create an executable program (.exe) or a dynamic link library (.dll). Large, complex projects may contain multiple .dll files.
A solution is a set of related projects, although it may also have just one project. Each time you create a new project, Visual Studio 2005 either adds it to an existing solution or creates a new solution.
Solutions are defined within a file named for the solution, and have the extension .sln. The .sln file contains metadata, which is basically information about the data. The metadata describes the projects that compose the solution and information about building the solution.
Visual Studio 2005 also creates a file with the same base name as the .sln file, but with the filename ...