Answer 1

Typescript is a superset of javascript ( including es6 and es7).
It implements many helpful features that is either planned or being developed to be added in future versions of javascript.
Moreover, it can detect many errors while writing and makes debugging way more easier.
That's why angular team chose to completely rewrite angular from scratch using typescript.
read https://thenewstack.io/typescript-getting-popular/
jQuery is just a library. Don't get them mixed.