Queries are the language with which you can communicate with Roam and ask it for help on whatever you’re working on.
If you become fluent in queries, then you can effectively ask yourself questions. Many users are scared of queries because the syntax looks complex. I prefer to look at it as flexible. There is a consistency in its logic that is easy to grasp when you understand the tools you have access to.
With practice, it becomes intuitive. Look for opportunities and take them. To get started, I highly recommend using queries to make repeatable any of the filtration processes you normally use linked references for. Play around with it and expand from there.
The Roam database page with the notes for the video can be found here.