This is an example of how to provide information on the images you use in your web pages to non-visual users...starring one of my favorite cartoon characters
Most browsers are set, by default, to display an image's ALT text in a small box called a "tool tip" when your mouse cursor rests over it, or if you turn off automatic loading of graphics in your browser. (NOTE: Turning off your browser's automatic loading of graphics is an excellent way to get an idea of what a non-visual user or user agent will display when accessing your page.) If you position your mouse cursor on the above title, you should see the ALT text "Stainboy" displayed in a tool tip box.
If you try the same technique with the graphic below on the left, please notice that no tool tip is displayed. This is because there is no ALT text supplied for this image.
Now, place your mouse over the graphic on the right. The tool tip will be displayed ... and I encourage you to follow the d-link for more information on our little friend!
Notice that a small Bobby's hat is displayed next to the the image on the left, the one without ALT text supplied. This indicates a Priority 1 error.