What happens with the if statement when it's true?

I started with HackerRank and I'm a bloody beginner.

So I've a question to this code:

'use strict';

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.trim().split('\n').map(string => {
        return string.trim();
    });

    main();    
});

function readLine() {
    return inputString[currentLine++];
}
/*
 * Create the function factorial here
 */
function factorial(n) {
    if (n === 1) {
        return 1
    } else {
        return n * factorial(n - 1)
    }
    return n;
}

function main() {
    const n = +(readLine());

    console.log(factorial(n));
}

I broke it down to something like this:

Let's depend n = 4;

4 === 1 ? // NO!
THEN:
4 * factorial(4-1) // n = 3;

3 === 1? // NO!
THEN:
3 * factorial(3-1) // n = 2;

2 === 1? // NO!
THEN:
2 * factorial(2-1) // n = 1;

1 === 1? // YES!
return 1;

What happens NOW? What happen with return 1 and what happend with all the other "loops"?! And why does it loop over and over, even when there is no loop?

Please try to explain as easy as possible.