Is there a difference between <i> and <em> tags?

Question

I have been using <em> tag to emphasize text in italics. I was wondering if there was a difference in characteristics or is it just a preference.

Answer 1

<i> = italic
<em> = emphasised

If you don't see any difference in your browser it doesn't mean it's the same in all browsers.

Answer 2

thanks Valentin, ill keep that side note in mind.