When to build\use Multiple Projects within a Solution

Question

i am a good but not so advanced .NET Developer. This is more of a Expert to juniors knowledge transfer request.

I was thinking, in Visual Studio you can Add projects inside a solution. Of-course these projects will carry different namespace.

My question is

• Why to build a project inside a solution
• When it is good\useful to build multiple project inside a solution.

Answer 1

I suppose you mean more than one project in a solution, right?

We use it mainly from a library perspective. You receive more than one assembly and in this way you can share or exchange only parts of you application. This is for example helpful if you have a bug in your application which touches only a part of your app. In this case you can fix and exchange only the bad assembly instead of the whole app.

Answer 2

It allows you to separate parts of an application. Your GUI, business logic, and data access can all be separate.

In addition, projects within a solution can reference each other with "project references". This ensures they all build with the same configuration: all Debug or all Release. Also, a projects can build when the projects they reference change.