Query rules are a hot new feature of SharePoint 2013 search. In essence, query rules are the infrastructure for query pipeline extensibility. Using query rules, we can create conditional rules that will intelligently respond to what the user is trying to search for.
Let's assume we have a knowledge center site that tags all of its assets (videos, images, documents, and so on) using the following taxonomy dictionary as shown in the following screenshot:

If a user searches for one of these terms, we should display a result on top of the other results, pointing the user to the knowledge center. A result that will always appear on top of other results is called a promoted result.
Promoted results are very similar to SharePoint 2010's best bets, but with one key difference: promoted results can react to taxonomy terms as well as matched keywords.
A promoted result, for the knowledge center we mentioned previously, will look as shown in the following screenshot:

Now, let's assume...