Block
further execution A callback function is a function passed into another function as an argument,
which is then invoked inside the outer function to complete some kind of routine or action.
A Promise is an object representing the eventual completion or failure of an asynchronous operation.
An async function can contain an await expression that pauses the execution of the async function
and waits for the passed Promise's resolution, and then resumes the async function's execution and
returns the resolved value. Remember, the await keyword is only valid inside async functions.
If you use it outside of an async function's body, you will get a SyntaxError.