<img src= alt= height= width= longdesc= />

The img element defines an image. It is an inline element. The main attributes are:

src

• Specifies a valid url for the image resource to be displayed
• It can be a relative or an absolute URL
• This attribute is required for every <img> element

alt

• Gives a replacement for the image, not a description of the image
• Displayed when the image is unavailable (could be a user option, eg mobile, blind, slow connection etc))
• A screen reader normally provides the alt text to the user
• Must be provided, used by both browsers and screen readers

width, height

• Defines width and height in pixels
• Should be provided

longdesc

• the URL of a file that provides additional information about the image
• Provide sufficient information for, say, a blind person to get an in depth description of the image
• Poorly supported by both browsers and screen readers. Almost certainly will be either removed or deprecated in XHTML5