what does this element do?

What is the meaning of the following element in HTML...

margin:0 0 0 847px  **!important;**  margin:0 0 开发者_运维百科0 848px..

Is it related to the browsers???

The reason for this particular order is that Internet Explorer did not interpret !important up to version 6. Thus, the second margin instruction applies to Internet Explorer <= 6 only.

This is called a browser hack. A good overview on browser hacks is here.

CSS rules marked !important take precedence over later rules. So in your case, the first, the first margin definition will be considered, i.e. 0 0 0 847px.

That's not HTML. That's something called CSS. It tells your browser how to format HTML. For example, this CSS is setting the margins around a certain element to be 847 pixels on one side.

It's CSS, not HTML.

The !important means that the HTML element that the CSS applies to should have a left-margin of 847 pixels and this should not be overridden by later styles. It which case the 848px following is ignored.