HTML 5 enables DNS Prefetching. This means that the domain name is resolved before the user decides to use the link. Usually this resolution of domain name is a time consuming process and can slow down a website. Prefetching feature in HTML 5 makes the process much faster. When the browser follows a link, prefetching ensures that the domain name, by that time, has already been cached.
Another related feature of HTML 5 is prerendering. This means that when your website shows up somewhere, the whole landing page would load up in the background and be at the ready state so that when the user clicks on it, the wheels can turn faster. This is another extremely effective way of increasing the speed of your website.
A big addition in HTML 5 is the new semantics framework. No longer does the developer rely on pre-defined semantics that are ambiguous and unclear. Earlier, as an example,
<div> would be followed by a class name created by the developer with the sole purpose of revealing a clearer idea of its purpose because simply
<div> does not cut it. This problem got resolved in HTML 5. Some of their new semantic additions include
footer and so on. Diagrammatically if some of these elements were used, they would be used as represented in the image.
The canvas tag is another interesting element of HTML 5. It is like creating your own big blank canvas on which you can draw, paint or color anything. Used as
What HTML earlier had was SVG which was Scalable Vector Graphic. The difference between canvas and SVG is that the former does not retain the whole model once the graphic is created so if you need to modify anything you need to redraw while SVG allows easier modification but retains the whole model which is bulky. Also, SVG works better with fewer and bigger objects and is based on shape while canvas is pixel based and works better with smaller objects which are more in number. For a more detailed comparison and understanding you could look at Jatinder Mann’s “Deep Dive into HTML5 Canvas”