HTML5  <canvas>  tag is used for creating graphics through scripting.

canvas tag is as follows,

the id attribute is an essential thing used for scripting.

Example 1 :

screenshot-localhost 2015-06-10 14-24-29

This shape can be created as follows,

HTML :

Script :

 

Example 2 :

Next we can create animated cloud and sun along with above image.

HTML :

Script :

hence the output will be as below,

screenshot-localhost 2015-06-10 14-44-19

The canvas tag can be used from creating different shape, we can add images and text into it and lot of functions are available for creating graphics.

Refer http://www.tutorialspoint.com/html5/html5_canvas.htm for more information.