iOS code signing and provisioning profiles in Xcode build settings vs Organizer submit to App Store

Question

I think I understand the meaning and use of the code signing and provisioning profiles in the apple development environment. I am confused however, there seam to be 2 places during app development @ submission to app store into which this info can ben entered:

1. In xCode build settings
2. Info is also asked (again) during submit process to app store

My questions:

(1).I can select a provisioning profile in the build settings.

1.1. What is this used for?

1.2 I use testflight to distribute to my beta testers, so I guess the selected provisioning profile here is overwritten by testflight when it makes its IPA for distribution?

(2). During submit of the app via the Xcode organiser you have to select yet again a "provisioning profile"

2.1. How does this relate to the provisioning profile selected in Xcode build settings?

2.2 What code signing identity is used for signing when submit to app store? The one selected in the Xcode build settings? Or is it automatically set when you login with your apple id during submit of the app (at the beginning of the submit to app store wizard)?

Answer 1

Actually it's possible to resign *.ipa files. I mean that you could build app with signing that set in target settings, generate ipa file and then resign it with another provisioning profile and certificated related to it.
So option for selecting app signing due submission to upstore is only flexible feature:
For example, you customer and ask developers to build app for app store submission but you don't want to share distrubution certificate and provisioning prifile for them. As result developers build app signed with developer certificate and share it with you. Then you as customer resign app with distrubition certificate and upload it for submission to app store.

Answer 2

You have different option build (debug, release ...) You should link a provisioning profile to this option build.

For exemple, when you select debug, you can run your application on your phone, with the provisioning profile for developer

If you select distribution, you will use the provisioning profile for distribution.

And for your team you should have an ad-hoc profile, with their iOS mobile UDID register for a ad-hoc provisioning profile.

When you try to launch the application, it will check the provisioning in order to see if it can launch the application. So you have to set the option build in order to match for what you want to do with this build.