When you are in a court case, the Judge or jury can notice facts that are well known and not disputed. You can think of these facts as things that most people agree on and are not likely to argue about. The Judge can also notice facts that can be easily checked using reliable sources, like a dictionary or a map.

If there is a jury in your court case, the Judge can tell them about these facts and how they were found. This helps the jury make a decision in your case. The Judge uses sources that are accurate and trustworthy to find these facts.