What are the variables used to store references to HTML elements in the code?

In JavaScript, you can store references to HTML elements using variables by selecting them through methods like document.getElementById(), document.querySelector(), or document.getElementsByClassName(). Here are some examples:

// Using getElementById
var header = document.getElementById('headerId');

// Using querySelector
var button = document.querySelector('.buttonClass');

// Using getElementsByClassName
var items = document.getElementsByClassName('itemClass');

In these examples:

• header stores a reference to an element with the ID headerId.
• button stores a reference to the first element with the class buttonClass.
• items stores a collection of elements with the class itemClass.

You can then manipulate these elements using the stored references.