You can find Facebook’s LIKE button everywhere. When a user klicks it, this is posted automatically on his wall (and on his friends’ walls too). If he has also written a comment, the familiar website abstract appears. That is, a picture along with a short description. But where does Facebook get this information?
For that purpose Facebook primarily uses Graph Meta Tags. A more detailed description can be found on the Open Graph page on Facebook. Attention: Facebook caches these data. Therefore it is no use to like again if data have been changed. For this reason Facebook has created the URL Linter, with this you can not only see what Facebook would see, but also reset the URL’s cache.
This post is also available in German
