Asynchronous Js

I have some trivial doubts regarding Asynchronous functions.

  1. When await keyword is encountered in async function, what does js exactly do ?
    does it skip the whole function and goes to next next instruction outside the function or will it try to execute rest of the code in async ( i personally think the first one as whatever inside a async func is supposed to be executed after the asynchronous instruction)

  2. Javascript has single thread and event based model. so if it encounters asynchronous code, i have read that it works in the background executing other instruction. what does executing in the background mean (if only it has single thread)?

  3. If in a code every instruction is depends on result of previous async function ,doesn’t executing in both synchronously and asynchronously becomes same ?

Kindly answer these question whenever you have time.

Thanks in advance.