According to Facebook’s glossary of terms, “Trending shows you the popular topics and hashtags that are being talked about on Facebook. You’ll see stories from people and Pages who’ve shared them with you or have shared them as Public.”
To see what’s trending, you can check the right side of your homepage and see a list of topics, much like Twitter.
You can then click on a topic that’s trending to see what people are saying about it (Provided that they have shared the posts as public).
Trending is not yet available to all users. However, you might have noticed while scrolling through your Timeline that if one of your friends is talking about a topic that is Trending, Facebook will tell you that it is a trending topic.
Will Facebook offer regional trending? It’s not clear yet.
Digital Marketeers are waiting for this next development to roll out to all users. This will be adding yet another measure for attainment for the brands active on Facebook.