Now we can embed the custom data attributes on all HTML elements. These new custom data attributes consist of Attribute Name and Attribute Value. And we have to name the custom attribute prefix with data-* (here * means we have to add some text or character). For example we created some functionality to display Tool-tip using Jquery or JavaScript. The Tool tip text comes from tooltip custom attribute (html5 extra attributes). before we used like this <div tooltip="This for Tool - tip text"...