Values from Web.template.config may be transposed to Web.config upon a build.

This may fill in details such as connection strings. In this paradigm, a Web.Debug.config will have instructions to make this happen upon debugging, and a Web.Release.config will put things back to defaults for the release builds. I don't understand how this stuff works yet.

Addendum 7/28/2015: I had it wrong. Values from Web.Debug.config get married into the template to make the Web.config file. You should not ever edit the template unless you are expanding functionality as opposed to changing canned settings.