ASP.NET Project Types
File - New - Project
instead of file - new - website
It acts like a different container together and the compilation model is different.
ScottGu provided some details when they were first launched: http://weblogs.asp.net/scottgu/archive/2006/05/08/445742.aspx
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The main difference is that the web application uses a .csproj file, which contains information about all the files in the project. What does it change? Using the website model, you can add new ones without visual studio, since adding new files does not require modifications to the csproj file, but using the web application model, you cannot. I personally prefer the web application type.
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People have identified a lot of differences, but let me add this broader touch:
Web application projects are architecturally compatible with other types of projects in .Net, whereas websites are diverting and really seem to be a throwback to the days of VS 2003.
For this reason, I find WAPs to be more elegant (especially when there are multiple projects in the solution).
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