What is redundancy and why is it used in distributed systems?

Redundancy in distributed systems refers to the inclusion of additional components or resources that are not strictly necessary for system operation but serve to enhance reliability and availability. It is used to prevent single points of failure, ensuring that if one component fails, others can take over, thereby maintaining system functionality. This approach improves fault tolerance and enables systems to recover quickly from failures, resulting in better overall performance and user experience. Additionally, redundancy can also facilitate load balancing and enhance data integrity across the distributed network.