This summary is not the rule. The rule text controls.
When a jury decides a criminal case, all jurors must agree on the verdict. This means every single juror has to vote the same way, whether that's guilty or not guilty. The jury announces this verdict out loud in the courtroom, in front of the judge and everyone else present.
If a case involves more than one defendant, the jury doesn't have to decide everyone's fate at the same time. If the jury reaches an agreement about some defendants but not others, they can announce a verdict for the ones they agree on right away. For any defendant the jury can't reach agreement on, that person can be tried again in a new trial later.
This rule protects defendants by making sure a guilty verdict only happens when every juror is convinced. It also gives courts a practical way to handle cases with multiple defendants, so the whole case doesn't get stuck just because jurors disagree about one person.