ALT text is used for visually impaired readers. It is usually attached to an image on your webpage. A reader, who is visually impaired and uses JAWS or Orca, will hear the ALT text in place of the image. At Organic SEO Specialists we recommend that you use ALT text in all your images. Not only does it help the visually impaired understand your website but it also shows the rest of the Internet community that you care. In HTML you can add ALT text with the following code (for example) :

<img alt="Search engine optimisation graph." src="/images/seo-graph.jpg"  width="300" height="450" />