What does innerHTML do in javascript?

The innerHTML property is used to get or set the HTML content of an element node.

Example: http://jsfiddle.net/mQMVc/

     // get the element with the "someElement" id, and give it new content
document.getElementById('someElement').innerHTML = "<p>new content</p>";

     // retrieve the content from an element
var content = document.getElementById('someElement').innerHTML;

alert( content );