An active-active redundancy setup utilizes all configured devices or paths at the same time, providing simultaneous use and immediate failover without noticeable downtime to users. It leverages multiple resources to handle the load and provides redundancy if one component fails, ensuring high availability. In contrast, an active-passive setup keeps standby systems idle until needed, which can introduce a delay in failover. Load balancing alone does not imply redundancy and relies on active-active environments to distribute traffic optimally. Lastly, a cold site is a backup location that is not readily available for immediate use and does not offer immediate failover.