Sync vs async

example.js

// Option 1: use a promise directly
let data;

function itTakesTime1() {
    return new Promise((resolve, reject) => {
        /* do something that takes time and produces a value */
        resolve(value)
    })
}

itTakesTime1().then(result => { data = result })


// Option 2: use a promise indirectly
async function itTakesTime2() {
    /* do something that takes time and produces a value */
    return value
}

data = await itTakesTime2()

/*
async is "syntactic sugar" for promises. Both options do the same thing.
Whenever you use async/await in your code, JavaScript uses promises under the hood.
Here's a great explanation of promises: https://javascript.info/promise-basics
And here's an explanation of async/await: https://javascript.info/async-await
*/