Why 'publish' website produces bin with one dll and build script produces bin with lots of dlls

I have made a scrip开发者_如何学JAVAt that uses the following command...

"C:\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe" "C:\Repositories\Software\trunk\main\upload\UploadWebsite.csproj" /p:Configuration=Release

This makes a website pre-compiled the bin directory has lots of dlls in it and tons of .compiled files...

However when I 'right click' on the project in visual studio I am able to 'publish' the website to a folder and this creates a pre-compiled website with only one dll. This is the preferable option im just wondering what the difference between the two is....?

The problem is that for a Website project, the publish feature of Visual Studio compiles everything into one dll, while the normal build operation compiles every page into a seperate DLL. Maybe these articles can help:

Publishing Web Application with MsBuild

How to publish a web site with MSBuild