HTML elements can include the attributes ALT or TITLE so that additional information is displayed when the viewer points to an image or hyperlink on the page in the browser. This functionality is most commonly used to supplement an image, but it can also be used to provide additional information about text links in Microsoft Internet Explorer.
The ALT attribute applies only to images and is recognized by all common browsers, whereas the TITLE attribute applies to hyperlinks, whether text or image, as well as to images; however, it may
not be recognized by browsers other than Internet Explorer.
Syntax
The following are examples of the syntax for the two attributes:
<img source="file:///C:/Photos/Mom1.jpg" alt="Picture of Mom">
-or-
<a href="file:///C:/Photos/Mom2.jpg" title="Photo of Mom">mother</a>
Notice that in the first case, the browser displays the image (Mom1.jpg) and displays the text "Picture of Mom" as a ScreenTip when the viewer points to the image; whereas in the second case, the browser displays the text "mother" as a hyperlink and displays the ScreenTip "Photo of Mom" when the viewer points to the hyperlink.
Internet Explorer recognizes the TITLE attribute when it is used in place of the ALT attribute for images, but other browsers (such as Netscape Navigator) may not. As a result, the following image reference
<img source="file:///C:/Photos/Mom1.jpg" title="Picture of Mom">
produces a ScreenTip when viewed with Internet Explorer, but may not when viewed with other browsers.