XCode中代码签名“Debug”或“Release”有什么意义？

Referring to the picture, I'm not understanding what is the point having an option to sign the "Debug" or "release" if it is useless as I have try to research. The only thing we are suppose to sign is the "Any iOS SDK". I've also did a binary diff to check that signing Debug and Release creates no difference in the _CodeSignature/CodeResources file. Referring to the picture, I'm not understand