What's the difference between Visual Studio Web Sites and Web Applications?

November already! It is again time for winter tyres and frosty mornings. From time to time, people ask me what's the difference between Visual Studio 2005's Web Sites (File/New/Web Site) and Web Application projects, for example File/New/Project/ASP.NET Web Application.

The answer can't be given in a single sentence, but basically web site are "projects" where a folder structure defines the set of files included, but web application have a traditional project file. To casual developers, or small projects, this might not make much difference but the professionals it does: if you use version control, I suggest that you use web applications instead of web sites, they will make your life much easier in most cases. Read more about the differences from MSDN.