This summary is not the rule. The rule text controls.
A grand jury doesn't serve forever. It stays active until a judge officially ends its service, but there's a time limit on how long that can last.
By default, a grand jury can only serve for six months. If more time is needed, the court that originally called the grand jury together can order it to continue past that six-month mark. Without that specific order, the grand jury's service ends at the six-month point.
For people involved in a case, this means grand jury investigations can't drag on indefinitely without court oversight. If prosecutors need more time to present evidence to a grand jury, they have to go back to the court and get approval to extend things beyond the normal limit.
