This example demonstrates:
Display images on a web page.
##Example analysis:
In HTML, images are defined by the <img> tag, <img> It is an empty tag, which means that it only contains attributes and has no closing tag. To display an image on the page, you need to use the source attribute (src). src refers to "source". The value of the source attribute is the URL address of the image.
The syntax for defining an image is:
<img src="url" alt="图片属性">
