Retina Display - Please Explain

Hello. I am thinking of purchasing an ipad with retina display or an ipad mini as a gift for my cousin.

I have one question though.
Does Retina display actually make a considerable difference? If I'm watching a video in standard definition , will it still appear better on a retina screen?

Thanks

This is LinuxForum, for Linux.

Neither the ipad nor the ipad mini run linux.

You need to ask elsewhere e.g. http://www.ipadforums.net/forumindex.php