The "title" attribute is the title= portion of an HTML tag which causes relevant information to appear in a little floating box over the text. The most common usage is to give more detail about a link. For example, <A HREF="http://everything2.com" title="Click here to visit Everything2!">Click Here</A> This is a link with the text "Click Here"...when the mouse hovers, the message "Click here to visit Everything2!" pops up...in Windows, this is called a tooltip.
A useful application of the HTML attribute "title" is often overlooked by webmasters. The "title" attribute is not restricted to hypertext anchors (or links), but rather can be used with virtually any tag... Therefore, a block of text marked off with <DIV>, <FONT>, <I>, <B>, and many others, can have an added level of description to be displayed to the user...very handy when tu usas otras idiomas...
Update 2006: Since the time of this node's original writing, quite a few web browsers have come and gone, and support for the title attribute has not been consistent.