The DOM Programming Interface
The HTML DOM can be accessed with JavaScript (and with other programming languages).
In the DOM, all HTML elements are defined as objects.
The programming interface is the properties and methods of each object.
A property is a value that you can get or set (like changing the content of an HTML element).
A method is an action you can do (like add or deleting an HTML element).
Example
The following example changes the content (the innerHTML) of the
element with id="demo":
Example
<html>
<body>
<p id="demo"></p>
<script>
document.getElementById("demo").innerHTML = "Hello World!";
</script>
</body>
</html>
Try it Yourself
In the example above, getElementById is a method, while innerHTML is a property.
The getElementById Method
The most common way to access an HTML element is to use the id of the element.
In the example above the getElementById method used id="demo" to find the element.
The innerHTML Property
The easiest way to get the content of an element is by using the innerHTML property.
The innerHTML property is useful for getting or replacing the content of HTML elements.
The innerHTML property can be used to get or change any HTML element, including <html> and <body>.