The Solution Explorer enables you to group and manage the many files that make up your application. A solution simply contains multiple projects (applications or assemblies). A project groups files related to its type. For instance, you can create a website, Windows Forms application, class library, console application, and more. The files inside the project containers represent your code in terms of web pages, forms, class files, XML, and other related items.
Figure 2.22 shows the Solution Explorer undocked from the IDE. The solution contains two applications (called projects). There is a Windows Forms application (OrderEntry) and a web application (WebSample).