How to select languages ​​in the Multilingual App Toolkit when localizing a Windows Store app?

Question

Microsoft

I am learning to localize Windows Store apps and I have 2 questions, I would be glad if someone could explain.
one). When you select a translation language in the Multilingual App Toolkit, some languages ​​have Microsoft Language Portal Provider and Microsoft Translator Provider icons. What do they mean?
2). Some languages ​​have nested languages. What does this mean and, for example, what is the difference between Malay [ms], Malay (Brunei Darussalam) [ms-BN], Malay (Malaysia) [ms-MY] ?