Redundant systems are setups designed to ensure reliability and continuous operation by having backup components. If one part fails, another can take over, minimizing downtime. This is commonly used in critical areas like data centers and aircraft to maintain functionality and safety. For example, a computer server might have multiple power supplies. If one power supply fails, the other can immediately provide power, preventing service interruptions. Similarly, network systems often use redundant pathways to ensure data can still flow even if one route is blocked or damaged.