How does JavaScriptCore works?

I've never met WebAssembly before. For its relation with JavaScript, I would like to research on JavaScriptCore first. For JavaScriptCore I have these problems:
- I think it's more like a back-end environment like `node` than a browser environment. How does it goes differently from `node`(except the differences of engines)?
- How does a front-end JavaScript project runs above it? If it can be just like running with a browser?
- How does a `node.js` project runs above it? Some node projects use the apis provided by `node.js`, how to deal with them?
- Whether it supports WebAssembly codes? Is a JS glue code needed? How does it goes differently from `wasi`?
- Why you are not importing node.js for iOS like Code App? For efficiency?
- `npm` is used to manage `node` projects. If it's possible to port it to `jsc`?
- I've noticed `view` to call system's api to view files. Is it possible to test front-end projects with it?
- I've also noticed that many apis are provided by `jsc`, changing the cursor shape for example. Can you tell me more details of it?