when is the bin folder used while installing web application using web setup project?

I tried installing my website on localhost.but the bin folder is empty.when exactly it is used.Theoritically all .cs file  gets compiled in to .dll and should be in Bin folder.Can anybody clearify what exactly happens on production server.

Hello

In realtime deployment, we first of all publish our website or web application at the local path. This will generate all the web pages and .dll that can be deployed on the production. All these dlls have to be placed inside the bin folder of the production web application and web pages have to be placed at WWWRoot.

Similarly all the 3rd party controls or our own layer dlls are also copied in the bin folder of the production web application.