This summary is not the rule. The rule text controls.
If you're fighting a motion for summary judgment but don't have the evidence you need yet, this rule gives you a way to ask the court for more time. You'll need to submit an affidavit (a sworn written statement) explaining why you can't get the facts or proof together right now to argue your side.
Once you explain your situation to the court, the judge has a few options. The judge can deny the other side's request for judgment right away, give you more time to gather affidavits, allow depositions to be taken, or let you do more discovery (the formal process of gathering evidence from the other side). The judge can also make any other order that seems fair given the situation.
Basically, this rule protects you from losing a case just because you haven't had enough time to collect your evidence. It stops the other side from rushing to win a case before you've had a fair chance to respond with real proof.