This summary is not the rule. The rule text controls.
If you're appealing a civil case, the district court can make you put up money or some other kind of security before your appeal moves forward. This protects the other side, making sure there's money available to cover their costs if you lose the appeal. The court decides how much security is needed and what form it takes, whether that's cash, a bond, or something else.
Some appellants don't have to do this. If a law specifically exempts you from this requirement, the court can't force you to post a bond. But if you don't fall into an exempt category, expect the court to set an amount based on what it thinks the appeal costs might add up to.
If someone acts as a surety (basically a backer who guarantees the bond), Rule 8(b) also kicks in and applies to them. That means the person or company backing your bond has their own set of responsibilities and rules to follow under this system.
