This summary is not the rule. The rule text controls.
Lawyers have to follow strict limits on what they say publicly about a case while it's being tried. This means an attorney can't make public comments that could unfairly influence a jury or damage someone's chance at a fair trial. The rule points to a specific ethics rule (Rule of Professional Conduct 3.6) that spells out exactly what lawyers can and can't say to the press or public during litigation.
For people involved in a case, this rule matters because it protects the fairness of the trial process. It stops lawyers from trying to sway public opinion or poison the jury pool through media statements, interviews, or press releases. If a lawyer breaks this rule, they can face discipline, which helps keep both sides focused on presenting their case in court rather than in the court of public opinion.