This summary is not the rule. The rule text controls.
Sometimes a piece of evidence is fair to use for one reason but not another. It might also be okay to use against one person in the case but not against someone else. When this happens, the judge can allow the evidence in, but only for its proper purpose.
If a lawyer asks for it, the judge must tell the jury exactly how they are allowed to use that evidence. The judge will explain what the jury can consider it for and what they must ignore it for. This keeps the jury from using evidence in a way that would be unfair to one side.
For example, if evidence is only allowed to help the jury understand one person's actions but not another person's guilt, the judge will make that clear. This rule protects people in a case from being unfairly judged based on evidence that was never meant to apply to them.
