CSS makes easier to make a tool tip. Now a days most of them using jquery Tool Tip, But the css Tooltip makes easy and makes less execution time. Personally I am a developer and I am also using this tooltip.
At First put your tooltip text into “rel” attribute. Then add a class “tooltip” into your HTML element.
That’s it , Your tooltip is ready.
Copy the code and use it. It is working in IE, Chrome ,Firefox