This summary is not the rule. The rule text controls.
If you agreed to guarantee someone else's debt, and your contract says the creditor has to try to collect from the original borrower first, this rule protects that agreement. It means you can ask the court to make the creditor go after the main borrower before coming after you.
In plain terms, this is about the order of who pays first. If you signed a suretyship contract that includes this kind of protection, the creditor can't skip straight to collecting from you. They have to first get a judgment against the original borrower and try to collect from them. Only after that can they come after you for the debt.
This rule only applies if your contract specifically created this right. If your agreement doesn't include this protection, the creditor can choose to sue you directly without going after the main borrower first. So the key question is what your original suretyship contract actually says.