How should I understand "Save for Development Deployment" in Xcode for iOS app?

1) As apple integrated testflight in itunes connect so when you select "Save for Ad Hoc Deployment" then you can distribute your app to users with designated devices. The app will be code signed with the distribution certificate. i.e it will use distribution certificate which we used to submit app on appstore. Previously when you use "Save for Ad Hoc Deployment" then you can create an ipa from development profile also. but now on it requires distribution certificate for "Save for Ad Hoc Deployment".

2) When you select "Save for Development Deployment" then you can distribute your app using development profile. it just like previously we did with "Save for Ad Hoc Deployment". i.e you can create your ipa file using development certificate also and you can distribute this ipa to your client and testers who's device id is present in your provisioning profile.

I think:

1.The purpose of "Save for Development Deployment" is that If you don't have the distribution certificate,you can also use development certificate to distribute your app!

2.The difference between "Save for Development Deployment" and “Save for Ad Hoc Deployment.” ,the difference is the type of certificate.

With Ad Hoc Development Apple gives you an URL to send to your registered testers. With Development Deployment, your users have to install the .ipa.