Yo can get the information about a YouTube video using the following. There is more available in the xml file than I have mentioned here.
$ytid= "; // YouTube Id
$url = "http://gdata.youtube.com/feeds/api/videos/". $ytid;
$doc = new DOMDocument;
$doc->load($url);
$title = $doc->getElementsByTagName("title")->item(0)->nodeValue;
$published = $doc->getElementsByTagName("published")->item(0)->nodeValue;
$updated = $doc->getElementsByTagName("updated")->item(0)->nodeValue;
To display a thumbnail use one of these:
http://img.youtube.com/vi/'.$ytid.'/0.jpg
http://img.youtube.com/vi/'.$ytid.'/1.jpg
http://img.youtube.com/vi/'.$ytid.'/2.jpg
http://img.youtube.com/vi/'.$ytid.'/3.jpg
http://img.youtube.com/vi/'.$ytid.'/default.jpg
http://img.youtube.com/vi/'.$ytid.'/hqdefault.jpg
Bless you for spending some time to describe the terminlogy for the newbies!