await setTimeout(resolve, 5000); does nothing extra, it's the same as setTimeout(resolve, 5000);

await will pause code execution of the containing function until a promise is resolved. The setTimeout function does not return a promise, it is not an async function. Hence, await is redundant, it doesn't do anything special in this case.

Your first bit of code does return a promise. It takes the legacy non-promise-based setTimeout function and turns it into a promise form. It then awaits this promise form.

You should learn about promises to gain a better understanding of what's going on. The key thing to note here is the difference between callback-based functions (like setTimeout) and modern promise-based functions.