You might have noticed that every time you search for something on Google, a panel on the right gives you a little information about the topic as well as links to Wikipedia and other sites. Right now Facebook appears to be working on something similar in a test that was discovered and revealed by some Twitter users.
Facebook has also said that it is working on the feature and it is currently in the testing phase. But since it's in the testing phase, we can't get too excited about it yet as there is no certainty that Facebook will release this feature. This feature is being run on iOS and on the desktop version of Facebook.
There are some improvements that need to done, problems like some topics displaying Wikipedia links while others don't still need to be fixed. But as noted, since Facebook is currently testing the feature, it makes sense that it might not be in its best form yet.
The feature surely sounds great especially for those of us who look up information on Facebook. If Facebook decides to give this feature a launch, it is something that's worth looking forward to.