This summary is not the rule. The rule text controls.
Here's a plain English summary of this rule:
If you make a copy of a document (like a photocopy, scan, or duplicate), that copy can be used in court just like the original. Courts don't require you to always track down the actual original paper if you have a good copy of it.
The only exception is when someone raises a real doubt about whether the original document is genuine. If there's an honest question about whether the original was faked, altered, or isn't what it claims to be, then a copy won't be enough. In that situation, the court will want to see the actual original.
In practice, this rule saves time and hassle. Most of the time, nobody disputes that a document is real, so copies work fine for evidence. But if someone has a real reason to think the original was tampered with or is fraudulent, they can push back and ask for the real thing.