audio function [0] meaning javascript code example

Example 1: play audio in javascript

var audio = new Audio('audio_file.mp3');
audio.play();

Example 2: javascript play audio

//play audio with from html audio element: 
document.getElementById('myAudioTagID').play();

//play audio with out html audio tag
var myAudio = new Audio('my_great_song.mp3');
myAudio.play();