When you are working in Visual Studio you have Solutions and Projects.
You can only work on one solution at a time - but one solution can have
many projects in it.
The way to add a project to a solution is
- right-click on the
"Solution" in the solution explorer and
- select Add-> Existing Project
- Select your project and it will be added to your solution.
In order for one project to see the classes and objects in the other then you must make a reference between the two.
One project can only reference the other though. Two projects can not
reference each other because the compiler will not know which one to
hope this will help you