posted 15 years ago
Did you mean "Unobtrusive JavaScript"?
If so, it's the technique where JavaScript is not mixed into the HTML markup, but is completely sequestered in the header and in external JS files. It's the same idea as using CSS for styling, moving style out of the markup and into stylesheets.
In this way the three parts of each page: structure, style and behavior are separated and not all munged together in the markup.
You can do it without the help of any library, but libraries such as jQuery make it easier to accomplish.