How to test iOS applications on iPhone during development?

Question

iOS

Recently became an official IOS developer. And I just can’t understand how you can test an application written in xcode on your devices (iPhone, iPad).
I read about this article, I did not find anything particularly sensible. There is something on the Internet about this, but everywhere xcode is old (I have xcode 6 beta).
Please tell me how you can test applications on devices. (on the developer site I already entered the data and even downloaded the file with the .mobileprovision extension, then I tried to upload it to xcode, it seemed to work), and then what to do?
ATP in advance)