Windows Phone or Windows Phone Silverlight, which one to choose?

Question

Windows phone

Hello,
I just began to study C # and develop an application on Windows Phone, I read a little, maybe I missed it somewhere, but I could not understand what "Windows Phone Silverlight" is?
I googled, read several articles about Windows Phone Silverlight, and the feeling came out that this is some kind of framework, an addition to the usual Windows Phone, or am I wrong?
questions arise:
1) Why, when creating a Windows Phone Silverlight application, he asks to select the Windows Phone platform (8.0 or 8.1), that is, it’s like a narrow direction for a particular platform, a picture arises in my head that the list of platforms is reduced with the use of Silverlight on which I can develop a Windows Phone app/
2) If Silverlight is some kind of addition, then why is it not, for example, AppBarButton ? That is, it turns out that XAML is different when using Silverlight, well then this is not an addition, but a completely different platform?
3) What is better to use for the development of Windows Phone Silverlight or just Windows Phone, should there be any pros and cons?
4) More specifically to the task. For example, I want to write a test application for receiving data from the server in JSON format and dynamically adding data to the mobile screen (of course, gradual addition by scrolling), using AppBarButton, read that for communication with the Internet, etc. it's better to use Silverlight (but you can do without it), but when using Silverlight, things like AppBarButton are not available to me, so I should draw such things from a regular Button ? that is, for an Internet Silverlight is a plus, but with other things I can lose?
Thanks in advance!

Answer 1

Silverlight died with wp 8, apps for 8.1 without Silverlight use the generic API.

Answer 2

Isn't Silverlight already dead? Don't use it.

Answer 3

It makes sense to use Windows Phone Silverlight if you want to support older OS versions. Windows Phone 8, the share of devices with this OS is about 30%, so there is a certain reason for this, but if there is no such task, then feel free to use the "Windows Phone Store app".