How does async and await work?

At first remeber two things

 Async just tells the compilar that if anywhere in the method a variable is declared with await name then please throw error, because await has reserved meaning please use it as keyword.

So async simply tells the compilar that await is going to be used beware of that , if it is used as variable name then throw warning..

await simply frees the UI thread to do other things and does not wait for the long task to complete , there is a state machine which tells the compilar when task is completed.