Question

As we post any url on facebook, it shows its meta-data(title, decription and thumbnail image), How can we achieve same thing in php or scripting language(javascript/jquery).

Answer 1

I believe, Facebook simply parses the html code of the Website behind the link and looks for <img /> tags. You can then choose any of the found images as picture for your link.

In PHP, you would fetch the websites HTML source via

$html = file_get_contents('http://...');

Then use regular expressions to find those <img /> tags.