What describes the relationship between redundancy and high availability?

The correct answer highlights that redundancy is essential for maintaining high availability. High availability refers to a system's ability to remain operational and accessible for a long period of time, minimizing downtime. Redundancy involves incorporating additional components or systems that can take over if a primary system fails.

When a system has redundancy, it means that there are backups available to handle requests and transactions even if one or more components fail. For example, in a cloud environment, deploying multiple instances of an application across different availability zones ensures that if one instance goes down, the others can continue to serve users without interruption. This continuous operation is what characterizes high availability.

Without redundancy, if a component experiences failure, the entire system might go down, leading to unacceptable levels of downtime. Therefore, redundancy serves as a foundational principle in designing systems aimed at achieving high availability, ensuring that failures do not disrupt the service or application in question.