This is not a fine and it may seem strange in common law jurisdictions in which civil and criminal liability are usually adjudicated in separate civil and criminal trials. In Spain both criminal liability and any civil liability arising from the criminal offense in question are usually determined in the same (criminal) proceeding. Thus, judges often demand that a bond be posted to cover possible civil liability determined during a criminal trial.

In other respects, it would be helpful if you actually post the text that you are translating so that we can have more context. Thanks!