Service Availability refers to the ability of a system or service to remain operational and accessible to users when needed. It is a critical aspect of service management, ensuring that users can rely on the service without interruptions. High availability is often measured as a percentage, indicating the proportion of time the service is functional. Factors affecting Service Availability include system reliability, maintenance schedules, and the effectiveness of incident response. Organizations often implement strategies like redundancy and failover systems to enhance availability. Monitoring tools are also used to track performance and detect issues before they impact users.