Labeling an image allows users to see a text message when they point at the image or see a text message instead of the image in the event they are using older Web browsers that do not display graphics, or for those users who deactivate the automatic image downloading preference in their Web browser.
To label an image, the alt tag is used within the image tag. The following demonstrates how this is accomplished:
<img src="yourimage.gif" alt="This is the text the user sees."/>